PE27.1-14 | Central Nervous System — Glossary

Recommended prophylactically in DMD from approximately age 10 years regardless of cardiac symptoms, to slow progression of dystrophin-associated dilated cardiomyopathy.

Carbonic anhydrase inhibitor that reduces CSF production by ~50%; used as a temporary medical measure in infants with post-haemorrhagic hydrocephalus of prematurity awaiting shunt surgery; side effects include metabolic acidosis.

The collection of conceptual, social, and practical skills that people learn to function in everyday life; the primary basis for severity classification in DSM-5 ID.

A CSF pattern characterised by markedly elevated protein with a normal or minimally elevated cell count; pathognomonic of Guillain-Barré syndrome and also seen in spinal cord compression and acoustic neuroma.

A custom-moulded brace controlling the ankle and foot; the most commonly prescribed orthotic device in CP to prevent equinus deformity and improve walking pattern.

Lower motor neuron cell bodies in the ventral horn of the spinal cord; the primary site of pathology in SMA; their degeneration leads to flaccid weakness with absent reflexes and fasciculations.

Fever-reducing medications (paracetamol, ibuprofen); reduce fever and discomfort but do NOT prevent febrile seizure recurrence — proven by randomised controlled trial.

Narrowing or obstruction of the cerebral aqueduct of Sylvius, the most common cause of congenital obstructive hydrocephalus; results in dilation of lateral and third ventricles with a normal fourth ventricle.

Meningeal inflammation with negative bacterial cultures, typically caused by viruses (especially enteroviruses); CSF shows lymphocytic pleocytosis, mildly elevated protein, and normal glucose.

Consistent use of one hand before 12 months of age, which in infancy indicates weakness or motor dysfunction of the opposite (less-used) hand and warrants urgent neurological evaluation.

A small molecule that promotes ribosomal readthrough of premature stop codons in the dystrophin mRNA; approved for DMD patients with nonsense mutations (~13% of DMD); taken orally three times daily.

A rare motor type of CP with cerebellar involvement characterised by hypotonia, broad-based gait, and incoordination.

Communication strategies and devices (picture boards, speech-generating devices) used for children who cannot communicate verbally; essential in non-verbal CP.

Inflammation of the meninges caused by bacteria, characterised by fever, meningeal irritation, and CSF pleocytosis with neutrophil predominance, elevated protein, and low glucose.

Turbid CSF with elevated pressure (>200 mmH2O), polymorphonuclear pleocytosis (hundreds to thousands/mm³), protein >100 mg/dL, and a CSF:blood glucose ratio <0.4; Gram stain and culture confirm the organism.

Thick gelatinous inflammatory material at the base of the brain (basal cisterns) in TBM; responsible for cranial nerve trapping, hydrocephalus, and vasculitis.

Live attenuated Bacille Calmette-Guerin (M. bovis) vaccine given at birth under India's NIS; provides 60–80% protection against disseminated TB (TBM, miliary) in children, though variable against adult pulmonary TB.

A milder allelic variant of DMD caused by in-frame mutations producing a truncated but partially functional dystrophin; presents later (~age 12–16) with slower progression; ambulation maintained into adulthood in many cases.

Benign Childhood Epilepsy with Centrotemporal Spikes; self-limiting focal epilepsy of childhood (5–12 years) with nocturnal facial/arm focal seizures; centrotemporal spike-waves on EEG; usually remits by puberty.

The Indian standardisation of the Stanford-Binet intelligence test; used for IQ measurement in Indian children.

Hypoxic-ischaemic encephalopathy resulting from intrapartum oxygen deprivation; a major preventable cause of intellectual disability and cerebral palsy in India.

Tight-junction endothelial layer separating circulating blood from brain parenchyma; disrupted by bacterial toxins and cytokines during meningitis, leading to cerebral oedema.

A neurotoxin injected into spastic muscles to transiently reduce tone by blocking acetylcholine release at the neuromuscular junction; used in CP for focal spasticity management.

A neurotoxin injected into spastic muscles to temporarily reduce tone by blocking acetylcholine release at the neuromuscular junction; used for focal dynamic spasticity management in CP every 3–6 months.

Involuntary flexion of both knees and hips when the examiner passively flexes the patient's neck, reflecting meningeal irritation.

A benzodiazepine rescue medication applied to the buccal mucosa at 0.2–0.3 mg/kg; increasingly preferred over rectal diazepam for prolonged febrile seizures due to ease of administration.

Enlargement of the calf muscles in DMD due to replacement of necrotic muscle fibres by fat and fibrous connective tissue; the calves appear large but are functionally weak — NOT true muscular hypertrophy.

A sodium-channel blocker AED used for focal seizures; must be avoided when there is a myoclonic seizure component as it worsens myoclonic epilepsy.

The bundle of lumbar, sacral, and coccygeal nerve roots that descend below the conus medullaris and float freely in CSF within the subarachnoid space, where they can be displaced rather than impaled by a lumbar puncture needle.

Third-generation cephalosporin providing excellent CSF penetration; empirical choice for bacterial meningitis in children >3 months; CONTRAINDICATED in neonates <28 days due to bilirubin displacement risk.

Hypotonia arising from a brain or upper motor neuron lesion; characterised by a lethargic or encephalopathic infant with preserved or brisk deep tendon reflexes and no fasciculations.

A group of permanent, non-progressive disorders of movement and posture attributed to disturbances in the developing fetal or infant brain, causing activity limitation.

A paediatric epilepsy syndrome characterised by frequent typical absence seizures, onset 4–10 years, 3 Hz spike-wave on EEG, and 60–70% remission by adolescence; first-line: ethosuximide or valproate.

Delicate fibrin web that forms when TBM CSF is left standing; caused by very high fibrinogen content; highly suggestive of TBM when seen.

Dilation of all ventricles due to obstruction of CSF flow in the basal cisterns (not within the ventricular system); the commonest type in TBM.

Impaired CSF resorption at the arachnoid granulations due to fibrosis following meningitis; all CSF pathways remain open (communicating type); may require VP shunt placement.

A WHO strategy integrating rehabilitation, equalisation of opportunities, and social inclusion for people with disabilities within community settings; promoted in India through RPWD Act.

A febrile seizure that is focal, lasts ≥15 minutes, or occurs more than once within a 24-hour period — carrying a higher risk of subsequent epilepsy.

Deficiency of thyroid hormone from birth due to thyroid dysgenesis or dyshormonogenesis; causes intellectual disability if untreated but is reversible if thyroxine is started within two weeks of birth.

Transient hypotonia and weakness in a neonate of a myasthenic mother, caused by passive transfer of maternal AChR antibodies; resolves within 2–8 weeks.

A rehabilitation intervention in which the unaffected limb is constrained to force intensive use of the affected limb, capitalising on neuroplasticity to improve upper-limb function in hemiplegic CP.

The continuation phase for TBM: isoniazid + rifampicin for 10 months (total 12 months); differs from pulmonary TB (4 months continuation only).

The tapered inferior end of the spinal cord, terminating at the L1-L2 vertebral level in adults and L2-L3 in neonates; the superior boundary below which lumbar puncture is anatomically safe.

Status epilepticus with prominent tonic-clonic motor activity and impaired consciousness; the most common and clinically obvious form of SE in children.

Abnormal cortical development (e.g., focal polymicrogyria, schizencephaly) resulting in disorganised motor cortex, causing hemiplegia and often drug-resistant focal epilepsy.

Highly sensitive and specific lateral flow assay for Cryptococcus neoformans capsular antigen in CSF and serum; the preferred rapid test for cryptococcal meningitis in immunocompromised patients.

CSF glucose divided by simultaneous serum glucose; normal 0.60–0.70; ratio <0.40 indicates abnormally low CSF glucose, seen in bacterial and tuberculous meningitis but NOT viral meningitis.

Elevation of WBC count in CSF predominantly composed of polymorphonuclear neutrophils (>80%), the hallmark of bacterial (as opposed to viral or tuberculous) meningitis.

Increase in CSF protein above 45 mg/dL, reflecting increased blood-brain barrier permeability from inflammation; markedly elevated in bacterial meningitis (>100 mg/dL) and very high in TBM (often >300 mg/dL); mildly elevated in viral meningitis.

The ratio of CSF glucose to simultaneously measured blood glucose; normally ≥0.6 (reflecting two-thirds blood glucose); a ratio <0.4 indicates abnormally low CSF glucose and suggests bacterial, TB, or fungal meningitis.

The ratio of CSF glucose to simultaneously measured serum glucose; a ratio <0.40 (40%) indicates abnormally low CSF glucose, characteristic of bacterial meningitis.

Congenital malformation characterised by cystic dilation of the fourth ventricle, hypoplasia of the cerebellar vermis, and an enlarged posterior fossa; a cause of obstructive hydrocephalus.

Developmental Assessment Scales for Indian Infants; a norm-referenced tool for assessing motor and mental development in Indian children from 0–30 months.

An alternative corticosteroid for DMD; similar efficacy to prednisolone with possibly less weight gain but higher risk of cataracts; dose is weight-based.

Corticosteroid given at 0.15 mg/kg IV q6h for 4 days before or with the first antibiotic dose in bacterial meningitis, reducing inflammatory cytokines and cochlear damage; strongest evidence for Hib meningitis.

Corticosteroid given in all stages of TBM at 0.4 mg/kg/day IV, tapered over 4–6 weeks; reduces cerebral oedema, vasogenic inflammation, and mortality; stronger evidence than in bacterial meningitis.

Corticosteroid given concurrently with the first dose of antibiotics in bacterial meningitis to reduce the inflammatory cascade, decrease blood-brain barrier permeability, and lower the risk of sensorineural hearing loss; most effective when given before or with the first antibiotic dose.

Progressive enlargement and dysfunction of the left ventricle with reduced ejection fraction; nearly universal in DMD by the late teenage years due to dystrophin deficiency in cardiomyocytes; now the leading cause of death in DMD.

A chromosomal disorder due to trisomy 21 (most commonly from nondisjunction), characterised by intellectual disability, typical dysmorphic features, and associated congenital anomalies.

A genetic epileptic encephalopathy caused by SCN1A loss-of-function mutations; onset with prolonged febrile hemiclonic seizures in the first year; drug-resistant; sodium-channel blockers (carbamazepine, lamotrigine) are CONTRAINDICATED.

Epilepsy that has not responded adequately to two appropriate, well-tolerated AED trials (ILAE definition); triggers referral for ketogenic diet, VNS, or epilepsy surgery evaluation.

An X-linked recessive progressive muscle disease caused by out-of-frame mutations in the dystrophin gene (Xp21), resulting in absent dystrophin protein, progressive muscle necrosis, and loss of ambulation typically in the early teenage years.

CP characterised by involuntary, uncontrolled movements including athetosis (writhing) and dystonia (sustained twisting), arising from basal ganglia injury.

A large structural protein (encoded by the DMD gene, Xp21) at the sarcolemma, linking the intracellular actin cytoskeleton to the extracellular matrix via the dystrophin-glycoprotein complex (DGC); absent in DMD, truncated in Becker MD.

A multiprotein transmembrane complex connecting dystrophin (intracellular) to laminin (extracellular matrix); disrupted in the absence of dystrophin, leading to sarcolemmal fragility and muscle fibre necrosis in DMD.

Structured developmental therapies (physiotherapy, OT, SLT, special education) initiated as early as possible (ideally before age 5) to exploit neuroplasticity and improve adaptive outcomes.

Electromyography/Nerve Conduction Studies — electrophysiological tests that distinguish neuropathic patterns (denervation in SMA) from myopathic patterns (muscle disease); key investigation in peripheral hypotonia.

Antibiotic treatment initiated on clinical grounds before culture and sensitivity results are available; in paediatric bacterial meningitis, ceftriaxone (100 mg/kg/day) combined with dexamethasone (0.15 mg/kg 6-hourly) is the standard empirical regimen per IAP guidelines.

Neuroendoscopic procedure creating a passage in the floor of the third ventricle to bypass an aqueductal obstruction; preferred for obstructive hydrocephalus in children >6 months; not effective for communicating hydrocephalus.

A procedure in which 10-20 mL of autologous blood is injected into the epidural space at or near the previous LP site to seal a persistent dural leak and treat refractory post-lumbar puncture headache.

A brain disease defined by any of: ≥2 unprovoked seizures >24 h apart; 1 unprovoked seizure with ≥60% recurrence probability; or diagnosis of an epilepsy syndrome.

Plantar flexion contracture of the ankle-foot due to heel-cord shortening in spastic hemiplegia; causes toe-walking and is managed with AFOs, botulinum toxin, and if needed, Achilles tendon lengthening.

A narrow-spectrum AED for typical absence seizures only; ineffective against GTCS; first-line for CAE without GTCS risk; side effects include nausea and hiccups.

A mutation-specific gene therapy strategy using antisense oligonucleotides to cause the spliceosome to skip a specific exon, converting an out-of-frame mutation to in-frame, restoring partial Becker-like dystrophin production.

Rapid, involuntary contraction of individual motor units visible on the tongue or limbs; a sign of anterior horn cell or lower motor neuron pathology (e.g. SMA).

A seizure associated with fever (≥38°C) in a child aged 6 months to 5 years, in the absence of CNS infection, metabolic disorder, or prior unprovoked seizures.

A febrile seizure lasting ≥30 minutes, or recurrent febrile seizures within 30 minutes without full inter-ictal recovery — the most serious complication of febrile seizures.

A prospective multi-centre study examining consequences of prolonged febrile seizures in children; demonstrated acute hippocampal signal changes on MRI DWI in some children, with risk of mesial temporal sclerosis on follow-up.

A pattern of craniofacial abnormalities, growth restriction, and intellectual disability resulting from prenatal alcohol exposure; the leading preventable cause of non-genetic ID in many populations.

Systematic approach to CSF analysis: Step 1 Appearance, Step 2 Cell count/differential, Step 3 Protein, Step 4 Glucose ratio, Step 5 Special tests — applied sequentially before synthesising a diagnostic category.

A neonate or young infant with generalised hypotonia, identified clinically by head lag on traction, rag-doll drape on ventral suspension, and slip-through on vertical suspension.

A seizure originating within networks limited to one hemisphere; may be focal aware (preserved consciousness) or focal impaired awareness.

Water-soluble prodrug of phenytoin; can be given IV or IM; rate limit 3 mg PE/kg/min; preferred over phenytoin due to IM compatibility and better cardiac tolerability.

The most common inherited cause of intellectual disability; caused by CGG triplet repeat expansion in the FMR1 gene on the X chromosome.

The resting posture of a severely hypotonic infant, with hips abducted and externally rotated and lower limbs lying flat on the mattress; a classic sign of generalised muscle hypotonia.

During prolonged SE, GABA-A receptors are removed from the neuronal surface membrane (clathrin-mediated endocytosis), reducing inhibitory neurotransmission and decreasing benzodiazepine efficacy — the molecular basis of SE self-perpetuation.

A seizure originating at some point within, and rapidly engaging, bilaterally distributed networks; includes tonic-clonic, absence, myoclonic, tonic, atonic, and epileptic spasms.

NAAT test detecting M. tuberculosis DNA and rifampicin resistance from CSF; sensitivity ~60-70% for TBM (lower than sputum); result in 2 hours; NTEP's first-line rapid test for suspected TBM.

Nucleic acid amplification test (NAAT) that detects M. tuberculosis DNA and rifampicin resistance within 2 hours; NTEP's first-line rapid diagnostic test for CSF when TBM is suspected.

Gross Motor Function Classification System — a validated 5-level ordinal scale (I = independent, V = fully dependent) classifying functional mobility in children with CP, used to communicate prognosis and plan therapy goals.

A five-level scale (I = least limitation, V = most limitation) that classifies the functional gross motor ability of children with CP; stable from age 4–5 years onward.

A clinical sign of proximal lower limb weakness in which the child rises from the floor by rolling prone, pushing onto all fours, then walking the hands progressively up the thighs to achieve standing; classically associated with DMD.

Streptococcus agalactiae, the leading cause of neonatal meningitis, acquired from maternal genital colonisation during delivery; gram-positive coccus in chains.

The topographic subtype of spastic CP where one side of the body (arm > leg) is affected; most common in term infants with unilateral cortical or subcortical lesions.

A surgical procedure that disconnects one cerebral hemisphere from the other and from subcortical structures, used for drug-resistant epilepsy in children with a damaged unilateral hemisphere.

A rare syndrome where prolonged unilateral seizures cause oedematous/ischaemic injury to the ipsilateral hemisphere, resulting in contralateral hemiplegia followed by epilepsy.

The most common viral trigger of febrile seizures in infants; causes roseola infantum characterised by high fever for 3–5 days followed by a maculopapular rash as fever resolves.

Regular radiographic monitoring of hip migration percentage in children with CP, especially non-ambulatory forms, to detect and prevent spastic hip dislocation.

Abnormal accumulation of cerebrospinal fluid within the ventricular system due to imbalance between CSF production and resorption, resulting in ventricular dilation and raised intracranial pressure.

Apparent ventricular enlargement due to brain parenchymal atrophy (brain shrinkage); NOT true hydrocephalus — there is no raised ICP and no excess CSF; shunting is contraindicated.

Abnormally reduced muscle tone, manifested by decreased resistance to passive stretch and abnormal postures in infancy; can be central (brain/UMN) or peripheral (LMN/NMJ/muscle) in origin.

Brain injury from intrapartum oxygen deprivation, the leading cause of CP in term infants in India; graded I–III by Sarnat classification; Grade II–III is associated with CP risk.

A chaotic, high-amplitude, multifocal spike-and-wave EEG pattern with no recognisable normal background; pathognomonic of West syndrome (infantile spasms); a neurodevelopmental emergency.

The mechanisms responsible for generating an individual seizure — involves an imbalance between excitatory (glutamate) and inhibitory (GABA) neurotransmission or abnormal ion channel function.

A key endogenous pyrogen and pro-seizure cytokine that elevates body temperature and directly enhances NMDA receptor-mediated neuronal excitability in the hippocampus.

CSF staining technique revealing the capsule of Cryptococcus neoformans as a clear halo around the yeast cell against a dark background; used to diagnose cryptococcal meningitis.

A written educational plan tailored to a child's specific strengths, limitations, and learning objectives; mandated under inclusive education frameworks for children with intellectual disability.

Unilateral upper motor neurone deficit acquired before two years of age, most commonly representing hemiplegic cerebral palsy from a static brain lesion.

A neurodevelopmental disorder characterised by significant deficits in intellectual functioning and adaptive behaviour, with onset during the developmental period (before 18 years), per DSM-5.

The first 2 months of anti-tuberculous therapy: isoniazid (H) + rifampicin (R) + pyrazinamide (Z) + ethambutol (E) given daily in weight-band fixed-dose combinations.

Insertion of a needle into bone marrow (tibia, femur) for emergency vascular access when IV cannot be established; delivers AEDs and resuscitation drugs as rapidly as IV.

A programmable implanted pump delivering baclofen directly into the intrathecal space to reduce severe or generalised spasticity or dystonia.

First-line ATT drug; bactericidal; dose 10 mg/kg/day in children; causes peripheral neuropathy (prevent with pyridoxine supplementation) and hepatotoxicity.

Isoniazid 10 mg/kg/day for 6 months given to asymptomatic close household contacts <5 years old of a sputum-positive pulmonary TB case to prevent primary TB and its disseminated complications including TBM.

A generalised epilepsy syndrome with morning myoclonic jerks, occasional GTCS, and rarely absence; onset 12–18 years; generalised polyspike-wave on EEG; lifelong AED therapy usually needed; valproate most effective.

Brain damage caused by severe unconjugated hyperbilirubinaemia in the neonatal period, leading to intellectual disability, hearing loss, and choreoathetoid cerebral palsy.

Inability to extend the knee beyond 135° when the hip is flexed to 90°, indicating meningeal irritation; moderate sensitivity for meningitis.

A severe drug-resistant epileptic encephalopathy with multiple seizure types (tonic, atonic drop attacks, atypical absence), slow spike-wave on EEG, and universal intellectual disability.

A broad-spectrum anti-epileptic drug of choice for focal onset seizures in children with hemiplegic CP; weight-based dosing, minimal drug interactions.

A broad-spectrum AED given intravenously at 20–60 mg/kg over 10–15 min as second-line SE treatment; increasingly preferred over phenytoin due to no cardiac monitoring requirement and favourable safety profile.

A thick, highly elastic yellow ligament connecting adjacent laminae of vertebrae; the first distinct resistance sensation felt as a lumbar puncture needle is advanced through the posterior spinal structures.

Gram-positive rod causing neonatal meningitis; intrinsically resistant to cephalosporins, mandating ampicillin in neonatal empirical regimens.

The hospital first-line benzodiazepine for established SE; dose 0.1 mg/kg IV (maximum 4 mg); onset ~2 min; prolonged duration of action 12–24 h via GABA-A receptor potentiation.

Diagnostic procedure to obtain CSF by inserting a needle into the subarachnoid space at L3-L4 or L4-L5 interspace; contraindicated with raised ICP, papilloedema, or focal neurological deficit until CT rules out a mass lesion.

Elevation of CSF WBC predominantly composed of lymphocytes (>80%); characteristic of TBM, viral meningitis, and fungal meningitis, in contrast to the neutrophilic pleocytosis of bacterial meningitis.

Head circumference greater than 2 standard deviations above the mean for age and sex (>98th centile); may be pathological (hydrocephalus, megalencephaly) or familial; requires serial OFC measurements to assess growth trajectory.

A female carrier of the X-linked DMD mutation who shows clinical signs of muscle weakness due to skewed X-inactivation, affecting approximately 10% of DMD carriers.

Measurement of CSF opening pressure using a calibrated vertical manometer tube attached via a three-way stopcock to the lumbar puncture needle; normal range in children is 70-180 mmH2O.

Atrophy and gliosis of the hippocampus associated with prolonged febrile seizures and temporal lobe epilepsy; best visualised on coronal MRI T2/FLAIR sequences.

DSM-5 severity level with IQ approximately 50–69 and limited deficits in adaptive functioning; most achieve independence in daily living with support and can attend inclusive schools.

Multiplex Ligation-dependent Probe Amplification — a molecular genetic technique used to detect copy number variants including the SMN1 exon 7 deletion in SMA diagnosis.

A molecular genetic technique used as first-line testing to detect copy number variants (deletions and duplications) in the dystrophin gene; identifies ~75% of DMD mutations.

British Medical Research Council staging: Stage I (alert, no deficit), Stage II (confused/drowsy or focal deficit/CN palsy), Stage III (stupor/coma or dense hemiplegia); predicts outcome.

Gram-negative diplococci causing meningococcal meningitis and septicaemia; associated with non-blanching purpuric rash and Waterhouse-Friderichsen syndrome.

Focal cerebral infarction in the neonatal period, most commonly in the middle cerebral artery territory, presenting with neonatal seizures and the most common cause of congenital hemiplegia in term neonates.

The level of membrane depolarisation at which a neuron fires an action potential; the immature brain has a lower threshold than the adult brain, making it more prone to seizures during fever.

The capacity of the developing brain to reorganise its neural connections in response to injury, allowing the unaffected hemisphere to partially compensate for loss of function; greatest in early childhood.

Elevation of CSF WBC predominantly composed of neutrophils (>80%); the hallmark of bacterial (pyogenic) meningitis, caused by rapid PMN recruitment in response to bacterial cell-wall components.

SE without prominent motor manifestations, presenting as prolonged absence, altered awareness, or subtle twitching in an encephalopathic child; diagnosed by EEG.

Respiratory support delivered via a mask (without intubation); indicated in DMD when FVC falls below 50% predicted, or with signs of nocturnal hypoventilation; delays respiratory failure and improves quality of life.

A fundamental property of CP — the underlying brain lesion does not advance; any apparent clinical worsening should prompt a search for a progressive neurological condition.

India's national TB control programme (formerly RNTCP); provides daily fixed-dose combination ATT in weight-bands; the current standard for TB treatment including TBM in India.

An antisense oligonucleotide that modifies SMN2 pre-mRNA splicing to increase production of full-length SMN protein; delivered intrathecally; approved for all SMA types.

Inflammation and thrombosis of perforating arteries in TBM, causing ischaemic infarcts in the basal ganglia, internal capsule, and thalamus; mechanism of focal neurological deficits.

Hydrocephalus caused by a blockage within the ventricular system, preventing CSF from reaching the subarachnoid space; the commonest cause is aqueductal stenosis.

The maximum head circumference measured with a non-stretchable tape around the most prominent occiput and forehead; plotted on gender-specific centile charts; crossing >2 centile lines upward is abnormal.

The initial CSF pressure recorded at manometry before any CSF is removed; reflects intracranial and intraspinal pressure equilibrium; elevated in bacterial meningitis, cryptococcal meningitis, and idiopathic intracranial hypertension.

Excessive CSF drainage by the VP shunt when upright, causing orthostatic headache (worse standing, better lying) and eventually slit-like ventricles that intermittently occlude the ventricular catheter; managed by reprogramming an adjustable valve.

A breathing pattern in which the chest wall draws inward during inspiration (while the abdomen protrudes), caused by intercostal muscle weakness with intact diaphragm; characteristic of SMA Type 1.

Worsening neurological symptoms or new tuberculomata 4–8 weeks after starting effective ATT, caused by immune reconstitution and enhanced inflammatory response to dying bacilli; treat by continuing ATT and increasing steroids.

Bacterial meningitis in which prior antibiotic therapy has modified the CSF profile: neutrophil count falls, lymphocytes rise, glucose may normalise, creating a CSF pattern that can mimic viral or TBM.

A delicate web-like clot that forms in CSF tubes containing TB meningitis CSF when allowed to stand; results from the high fibrinogen/protein content and is a macroscopic diagnostic clue to tuberculous meningitis.

Combined vaccine against diphtheria, tetanus, pertussis, Haemophilus influenzae type b, and Hepatitis B, given at 6, 10, and 14 weeks under India's Universal Immunization Programme.

Hypotonia arising from the anterior horn cell, peripheral nerve, neuromuscular junction, or muscle; characterised by an alert infant with absent or reduced deep tendon reflexes and possibly fasciculations or elevated CK.

Ischaemic injury to periventricular white matter, predominantly in preterm infants, producing symmetrical or asymmetrical corticospinal tract injury and spastic CP.

Low-attenuation (dark) halo around the ventricles on CT in active hydrocephalus, representing transependymal seepage of CSF under raised pressure through the ependymal lining into the periventricular white matter.

An autosomal recessive disorder of phenylalanine hydroxylase deficiency causing accumulation of phenylalanine; leads to intellectual disability if untreated but is preventable with a low-phenylalanine diet.

A sodium-channel blocking AED given IV at 15–20 mg/kg at ≤1 mg/kg/min with ECG monitoring; MUST NOT be given IM (crystallises); second-line SE treatment.

An abnormal increase in the number of white cells in cerebrospinal fluid; polymorphonuclear (neutrophil) pleocytosis suggests bacterial infection, while lymphocytic pleocytosis suggests viral, TB, or fungal infection.

A positional, frontal or occipital headache occurring 24-48 hours after LP, caused by persistent CSF leakage through the dural puncture site leading to intracranial hypotension; managed with rest, hydration, analgesics, and epidural blood patch for refractory cases.

A transient period of depressed consciousness, confusion, or drowsiness following a seizure; typically lasts minutes to 30 minutes in febrile seizures — recovery to baseline is a reassuring sign.

A genetic syndrome caused by loss of paternal 15q11-13 expression (deletion or UPD); presents as severe neonatal hypotonia with poor feeding, evolving to hyperphagia and obesity in childhood; a cause of central hypotonia.

The corticosteroid standard of care for DMD; delays loss of ambulation by 2–5 years and preserves respiratory and cardiac function; dose is strictly weight-based in children.

Brainstem-mediated reflexes (Moro, ATNR, grasp) present in neonates and normally suppressed by cortical maturation by 4–6 months; their persistence beyond expected age suggests CNS pathology such as CP.

A potentially fatal complication of prolonged high-dose propofol infusion (>4 mg/kg/h for >48 h), causing metabolic acidosis, rhabdomyolysis, renal failure, and cardiac failure; particularly dangerous in children under 15 years — propofol is contraindicated for refractory SE in this age group.

Increase in size of a muscle or organ due to infiltration by non-functional tissue (fat, fibrous tissue) rather than growth of functional cells; seen in the calves in DMD.

The principle that out-of-frame (frameshift) dystrophin gene mutations cause severe DMD (absent protein) while in-frame mutations cause milder Becker MD (truncated protein); predicts phenotype in ~90% of cases.

Positioning an unconscious or seizing child on their side with the upper leg bent and the head tilted back; protects the airway from aspiration of vomitus or secretions during a seizure.

A benzodiazepine rescue medication given rectally at 0.5 mg/kg body weight for seizures lasting ≥5 minutes; used as community first-line treatment for prolonged febrile seizures.

SE that has failed to respond to an adequate benzodiazepine and one second-line AED; requires ICU management with anaesthetic agents and continuous EEG monitoring.

Small granuloma in the subependymal or subpial cortex formed during haematogenous dissemination of primary TB; rupture into the subarachnoid space initiates TBM.

First-line ATT drug; bactericidal; dose 15 mg/kg/day; causes orange discolouration of urine and secretions; potent CYP450 inducer (reduces levels of many co-administered drugs including phenytoin and carbamazepine).

Antibiotic chemoprophylaxis for close contacts of meningococcal disease (10 mg/kg/dose every 12h × 2 days) or Hib disease (20 mg/kg/day once daily × 4 days) to eliminate nasopharyngeal carriage and prevent secondary cases.

Rights of Persons with Disabilities Act, 2016 — Indian legislation recognising intellectual disability as a specified disability, entitling individuals to educational support, welfare benefits, and disability certification.

A mutation in the voltage-gated sodium channel gene associated with Dravet syndrome and febrile seizures-plus (FS+); reduces sodium channel function in inhibitory interneurons, lowering the seizure threshold.

Regular spinal radiography in non-ambulatory DMD patients to detect progressive curvature; surgical fusion is considered when Cobb angle exceeds 30–40 degrees to prevent restrictive lung disease.

A transient occurrence of signs and/or symptoms due to abnormal, excessive, or synchronous neuronal activity in the brain.

A neurosurgical procedure that divides selected dorsal (sensory) rootlets to reduce spasticity in carefully selected children with pure spastic diplegia.

The most common neurological sequela of bacterial meningitis, caused by cochlear inflammation via the cochlear aqueduct; most frequent with pneumococcal meningitis (~20%); all survivors require audiological screening.

A muscle enzyme released into the bloodstream during muscle fibre necrosis; markedly elevated in DMD (10–100x ULN, typically 5,000–50,000 U/L); decreases in later non-ambulatory stages as muscle is replaced by fibrofatty tissue.

DSM-5 severity level with IQ approximately 20–34 and markedly limited adaptive functioning; requires substantial support for all major life activities.

The most common VP shunt complication; obstruction of the ventricular catheter by choroid plexus, blood clot, or debris; presents with recurrence of raised ICP symptoms and ventriculomegaly on CT; managed by shunt revision.

Infection of the VP shunt device, most commonly by Staphylococcus epidermidis; risk highest in the first 6 months post-insertion; requires shunt removal, IV antibiotics, external ventricular drainage, and eventual re-shunting.

Excess ADH secretion triggered by CNS inflammation, causing water retention, hyponatraemia, and concentrated urine despite plasma hypo-osmolality; treated by fluid restriction in meningitis.

Excessive drooling due to oropharyngeal motor dysfunction in CP; managed with oral glycopyrrolate or BTX-A injection to the salivary glands.

A febrile seizure that is generalised (bilateral), lasts <15 minutes, and occurs as a single episode within a 24-hour period — the most benign subtype.

The most severe form of SMA, with onset before 6 months, absent deep tendon reflexes, tongue fasciculations, paradoxical breathing, and failure to achieve sitting; fatal before age 2 without disease-modifying treatment.

Survival of Motor Neuron 1 gene on chromosome 5q13; its homozygous deletion or pathogenic variant causes SMA; its protein product is essential for anterior horn cell survival.

The most common motor type of CP (~80%), characterised by velocity-dependent increased tone, hyperreflexia, and positive Babinski sign due to corticospinal tract injury.

A subtype of spastic CP with predominantly lower limb involvement, bilateral; the characteristic CP type of preterm infants with periventricular leukomalacia.

Spastic CP affecting all four limbs severely; typically from severe global HIE or major brain malformation; highest burden of comorbidities (epilepsy, ID, feeding difficulties).

An autosomal recessive neuromuscular disease caused by SMN1 gene deletion, leading to anterior horn cell degeneration; classified by age of onset and maximal motor function (Types 0–4); now treatable with nusinersen, risdiplam, or onasemnogene.

A seizure lasting ≥5 minutes (ILAE T1 threshold — requires treatment) or ≥2 seizures without inter-ictal recovery; T2 (≥30 min) marks onset of long-term neurological consequences.

Gram-positive lancet-shaped diplococci and the commonest cause of bacterial meningitis in children >3 months; carries highest risk of deafness and neurological sequelae.

The space between the arachnoid mater and the pia mater, filled with cerebrospinal fluid and containing the cauda equina nerve roots in the lumbar region; the target compartment of lumbar puncture.

Pus collection in the subdural space, a complication of bacterial meningitis particularly with Hib and pneumococcal disease; presents with persistent fever and focal deficits; may need neurosurgical drainage.

Tonic downward deviation of both eyes in infants with raised ICP from hydrocephalus, with sclera visible above the iris; caused by pressure on the midbrain pretectal area impairing upgaze; a specific sign requiring urgent investigation.

The 5-minute ILAE operational threshold at which a seizure is considered unlikely to self-terminate and benzodiazepine treatment must be administered immediately.

The 30-minute ILAE threshold after which irreversible neurological consequences (hippocampal neuron loss, excitotoxicity, systemic complications) begin to accumulate.

A barbiturate anaesthetic agent used for refractory SE under ICU conditions; loading dose 2–4 mg/kg IV then 2–8 mg/kg/h infusion; potent GABA-A agonist; requires intubation and ventilation.

A technique for distinguishing traumatic tap from subarachnoid haemorrhage by comparing RBC counts in sequentially collected CSF tubes; in traumatic tap, RBC count decreases from tube 1 to tube 3; in true SAH, counts remain approximately uniform across all tubes.

Transient focal weakness of a limb following a focal seizure (post-ictal weakness); typically resolves within minutes to hours; its presence indicates a focal brain lesion until proven otherwise.

A bedside manoeuvre in which the infant is pulled from supine to sitting by the wrists; assesses for head lag — excessive head lag (beyond 4 months) indicates hypotonia.

Downward displacement of the uncus of the temporal lobe through the tentorial notch secondary to elevated supratentorial pressure; the catastrophic complication of performing LP in a patient with raised ICP, presenting as sudden loss of consciousness, ipsilateral pupil dilation, and contralateral motor deficit.

LP where the needle traverses an epidural vein, contaminating CSF with blood; produces spuriously elevated WBC and protein; distinguished from subarachnoid haemorrhage by clearing of blood from tube 1 to tube 3 and absence of xanthochromia.

An LP complication in which the needle punctures an epidural or subarachnoid blood vessel, producing bloody CSF; distinguished from true subarachnoid haemorrhage by progressive clearing of RBCs across sequential tubes and absence of xanthochromia in the supernatant.

Meningeal infection caused by Mycobacterium tuberculosis, presenting with subacute onset, lymphocytic CSF pleocytosis, markedly elevated protein, and characteristic basal exudate on imaging.

Clear or xanthochromic CSF with elevated pressure, lymphocytic pleocytosis (<500/mm³), markedly elevated protein (>100-500 mg/dL), low CSF glucose (ratio <0.4), and pellicle formation; AFB smear has low sensitivity (~20-40%); MTB PCR and culture confirm.

A neurocutaneous syndrome (autosomal dominant, TSC1/TSC2 mutations) causing cortical tubers, epilepsy, and intellectual disability; identified by ash-leaf macules and seizures.

An imaginary horizontal line connecting the highest points of the posterior superior iliac crests, which crosses the L4 spinous process or the L4-L5 interspace; the primary surface landmark for identifying the safe lumbar puncture level.

A brief (5–20 s), abrupt-onset, abrupt-offset episode of staring with unresponsiveness and no postictal phase; associated with 3 Hz generalised spike-wave on EEG; provoked by hyperventilation.

A broad-spectrum AED effective for generalised epilepsies (absence, myoclonic, tonic-clonic); teratogenic (neural tube defects) — requires contraception counselling in adolescent females.

Glycopeptide antibiotic added to ceftriaxone in empirical meningitis therapy for children >3 months to cover penicillin/cephalosporin-resistant Streptococcus pneumoniae.

A bedside manoeuvre in which the infant is held prone on the examiner's hand; a hypotonic infant drapes passively ('rag-doll sign') rather than maintaining a horizontal anti-gravity posture.

Abnormal dilation of the cerebral ventricles, measured on imaging by the frontal horn width to internal skull diameter ratio (>0.33 is abnormal) or by absolute measurements compared to age-specific norms.

Surgical device consisting of a ventricular catheter, one-way pressure valve, and peritoneal catheter that diverts CSF from the lateral ventricle to the peritoneal cavity for absorption; the commonest surgical treatment for paediatric hydrocephalus.

A standardised rating scale assessing communication, daily living skills, socialisation, and motor skills; used to evaluate adaptive functioning for DSM-5 ID criteria.

Clear CSF with normal or mildly elevated pressure, lymphocytic pleocytosis (<500/mm³), mildly elevated protein (50-100 mg/dL), and a normal CSF:blood glucose ratio (≥0.6); Gram stain negative, culture sterile, enterovirus/HSV PCR may be positive.

Bilateral adrenal haemorrhage causing acute adrenal insufficiency in fulminant meningococcaemia; presents with purpuric rash, shock, and adrenal crisis; a life-threatening complication.

A catastrophic epileptic encephalopathy of infancy (onset 3–12 months) with epileptic spasms in clusters, hypsarrhythmia on EEG, and psychomotor regression; requires urgent ACTH/prednisolone + vigabatrin.

Yellow discolouration of CSF indicating previous haemorrhage (subarachnoid haemorrhage), severe hyperbilirubinaemia, or very high protein; differentiated from traumatic LP by equal blood in all CSF tubes and persistence beyond 2 hours.