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ataxia. contents. Ataxia definition path physiology Causes History & examination Investigations Overview on the most common causes. Defention: derived from greek word meaning irregularity The coordination of movement depend on:
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contents • Ataxia definition • path physiology • Causes • History & examination • Investigations • Overview on the most common causes
Defention: derived from greek word meaning irregularity • The coordination of movement depend on: • Cerebellum & its connection….cerebellar ataxia( ataxia gait, limb incoordination,tremer,dysarthria, nystagmus) • Sensory feed back….sensory ataxia (ataxia of gait &limb at dark,loss of proicption,+ve romberg test)
cerebellum • Vestibulocerebellum” • Input: vestibular ,visual path • Out put:feed back to the vestibular nuclie • Lesion :disturbe equlibrum,wide base gait ,nystagmus • Spinocerebellum: • Input ;somatosensory via the spinal cord • Output: brain stem reticular ,lateral vestibular nuclie • Lesion :vermis truncal ataxia, lateral limb ataxia
cerebellum • Cerebrocerenellum: • Input:cortico pontine • Output:feedback dentate,thalamus..cortex motor,premotor • Lesion:impair complex voulntry movement, smooth &persize
cont • Clinical assessment is complicated by the fact that few ataxic patient have pure cerebeller disease, additional pathology is often present, brain stem,spinal cord,.. • Ataxia also may be due to weakness
Ataxia causes • Acquired: • Hereditary: known metabolic defect not known metabolic defect
Acquired causes • Infection: posterior fosse abscess, cerebellitis • Vascular:Hge, infarction, TIA • Demyelinating: MS, Sensory PN( miller fisher) • Malignancy: tumor • Toxin &drug: INH, lithium,cyclosporin,cystosine arabiniside, phyntoin, procainamide • Paraneoplastic • Metabolic: vit E deficiency , hypothyroidism
hereditary • Known metabolic def • DNA repair defect • Unknown etiology
Hereditary known metabolic defect • Intermittent • Progressive
Hereditary causes • Ataxia is prominent feature • Intermittent: • Hyperammonimea,aminoacidurea,disorder of pyrvate &lactate • Progreesive: • Abetalipprotenimea • Leukodystrophy:metachromatic • Mitochondrial encephalomyopathy • Wilson disease • Sialdosis • Other:hexamindase def,sphyngomylin storage dis, ceroid lipfuscinosis,cholstrenolosis……
Defect DNA repair • ataxia telengctasia • Xerderma pigmentosa • Cocakayne syndrome
Hereditary ataxia with unknown etiology(degenerative) • AR early on set before 20y • Friedreichs ataxia • Early onset cerebellar ataxia with non fredreichs Retained tendon reflex Hypogonadism Myclonus Childhood defness Congintal defect optic atrophy +_ MR Cataract & MR Pigmented retinopathy • Late onset
Hereditary with unknown metabolic defecspinocerebllum degeneration • AR: <20y • AD: >20y
Herdiatry AD • ADCA I: ataxia, opthalmoplasia,optic atrophy,dementia, extraprymidal(include machado-joseph) • ADCA II: ataxia with pigment maculopathy+_ opthalmoplasia or extraprymidal sign • ACDAIII: pure ataxia • Periodic dominant ataxia
History &exam • onset Acute :vascular subacute: others • Course: • episodic( MS,drug,TIA, foramen magnum compression, intermittent hydrocephalus colloid cyst, inherited met, dominant periodic ataxia • Progressive: inherited, tumor, paraneoplastic, hydrocephalus, vit E deficiency ,ms, hereditary motor sensory neuropathy
c/p • Opsclonus, ocular flatter: viral cerebellitis, Paraneoplastic • Extraprymidal: ataxia telngactasia,late onset ataxia, wilson disease • Myclonus:mitochondrial encephalopathy,sialidosis
C/P • Hyporeflxia: (loss of propiception): FA,other inherited degenerative,vitE def,hypothyrodism,alcholic,miller fisher,leukodystrophy,PN,ataxia telengctasia,xerderma pigmentosa, refsum disease • Defness: several inherited ataxia,mitochodrial,refsum disease
c/p • Dementia: hydrocephalus, some degenerative • Optic atrophy: FA late,MS, inherit, alcholism • Retinopathy: mitochondrial encephalopathy
Systemic manifestation • Hair loss: hypothyrodism. • Skin: telengectasia conjactiva,nose,ears…ataxia Telengectasia • Light sensitivity: xeroderma pigmentosa • Dry skin: refsum, hypothyrodism, cockayan syndrome
systemic manifestation • Eye: kayser-fleisher ring(wilson) • catarct (mitochondrial encephalopathy) retinal angioma :von hipple lindau • Fever: abscess, cerebillites • Vomiting: stroke, tumor, metabolic • Hepatomegaly: wilson • Heart disease: cardiomyopathy FA, conduction block.(.mitochondrial encephalopathy)
other • Immune deficiency :AT • Malnutrition: vit E def, alcholism • Skeletal deformity: FA,other early onset spinocerebeelum degeneration, hereditary motor &sensory neuropathy • Hypogonadism: mitochondrial, AT.
investigation • R/O acquired causes : • CT brain, MRI • LP • EMG,NCS • TFT • lipid
FA • The most common of AR ataxia, 50% of heridatry ataxia • Gene map chr: 9q13,trinucletide repeared disease • Pathology: • Spinal cord: • Postrior colum (loss of reflex) • Corticospinal tract(weakness ,upgowing toes) • Spinocerebeller:ataxia,dysarthria • Loss of purkinge cell in cerebellum,pontine medulla,optic n • PN • Mycardial muscle fiber
C/P • Onset:< 25y • Begin gait ataxia early, dysarthria later • PN,sensory &cerebeller ataxia • Weakness • Optic atrophy 25%,defness 10% • O/E: pescavus ,hammertoes,kyphlscliosis • Cardiomyopathy • Dec or absent reflex, loss vibration, up going toes,ataxia ,dysarthria, romberg +ve
diagnosis • Clinical • Lab: • MRI brain: early n,then cerebeller atrophy • MRI spine: may atrophy cervical part • NCS:sensory absent in LL, slow in UL • ECG:wide spread T wave ,VH • ECHO:symetrical cocentric VH • Gene study