Cerebellar syndrome Flashcards
Approach to cerebellar syndrome
DANISH Dysdiadochokinesis Ataxia Nystagmus Intention tremor Scanning dysarthria Hypotonia/hyporeflexia
Upper Limb
Dysdiadochokinesia
Impaired finger nose test - dysmetria (past pointing) and intention tremor with voluntary movement
Rebound phenomenon on pronator drift
Hypotonia, hyporeflexia - loss of cerebellar reinforcing signals
Lower Limb
Impaired heel shin test
Hypotonia, hyporeflexia
Broad based gait with ataxia, falls towards side of lesion
Unable to tandem walking (heel to toe)
Romberg test usually negative
Cranial Nerve
Nystagmus - fast component towards side of lesion
Broken pursuit
Hypermetric saccades
Slurred speech with staccato character - broken syllables, hesitancy (British Constitution)
Head titubation
Clues
Age - younger (hereditary), older (alcoholic)
Scars over posterior fossa
Lip telangiectasia
Walking aids
Dorsal column sensory loss, pes cavus = Friedreich’s ataxia
What are the causes of cerebellar syndrome?
PASTRIES Paraneoplastic cerebellar syndrome Alcoholic cerebellar degeneration Sclerosis (MS) Tumour (posterior fossa) Rare hereditary (Friedrich’s ataxia, SCA, AT) Iatrogenic (phenytoin toxicity) Endocrine (hypothyroidism) Stroke (brain stem)
Unilateral
- Stroke - ataxic hemiparesis, PCA infarct, Benedikt’s
- Space occupying lesion - CPA, cerebellar, posterior fossa
- Multiple sclerosis
- Multisystem atrophy
- Syringomyelia
Bilateral
- Congenital: Chiari malformation, Dandy Walker, Joubier
- Hereditary
> AD: spinocerebellar ataxia
> AR: Friedreich’s ataxia, ataxia telangiectasis
> XLR: Fragile X
- Acquired: use Vitamin D algorithm
- Drugs - phenytoin, carbamazepine, lithium
- Alcohol
- Infection - syphilis, HIV, toxoplasmosis, Lyme, CJD, enterovirus/coxsackie, HSV encephalitis, herpes
- Autoimmune
> Systemic: SLE, Neurosjogren
> CNS: MS, NMO
> Peripheral: MFS - looks like pancerebellar
- Metabolic - Wilson’s, hypo/hyperthyroidism, B12 deficiency
- Paraneoplastic syndrome
- Bilateral cerebellar stroke
- Degenerative: MSA-C
Why does cerebellar lesion result in hypotonia?
Deep cerebellar nuclei send reinforcing signals to motor cortex and cerebellocortical tract increases tone (to normal tone)
Acute cerebellar dysfunction - loss in signal with slight decrease in tone
Chronic cerebellar dysfunction - motor cortex compensates with increased intrinsic activity
What drugs result in cerebellar syndrome?
Phenytoin
Lithium
Carbamazepine
Phenobarbitone
Chemotherapy
What are the primary tumours that affect cerebellum?
Medulloblastoma
Astrocytoma
How would you localise cerebellar lesions?
Vermis lesion (midline cerebellar) affect trunk and axial muscles -> truncal ataxia
Neocerebellum (cerebellar hemispheres) -> ipsilateral limb ataxia
What is pendular reflexes?
Knee reflex swinging several times to and fro like a pendulum in cerebellar lesion
What is paraneoplastic cerebellar degeneration
Paraneoplastic manifestation in cancers of ovary, uterus, breast, lung, Hodgkin lymphoma
Immune mediated - high autoantibodies titers cross react with nervous system cells
- Anti-Yo (anti-Purkinje cell antibodies) in gynae and breast cancer
- Anti-Hu (anti-neuronal nuclear antibodies) in small cell ca, prostate, sarcoma, neuroblastoma
Onset of symptoms precede diagnosis of tumour
Usually bilateral cerebellar dysfunction
(Unilateral dysfunction is against diagnosis)
What is staccato and scanning speech
Staccato - alternating normal, low or explosive syllables
Scanning - same tone for whole phrases - robotic
Natural evolution of cerebellum
1st. Fluconodular - eye movement -> saccade, pursuit
2nd. Vermis - truncal control -> truncal ataxia, head titubation
3rd. Neocerebellum - limb control -> fine motor control
What is this scar?
Posterior fossa scar
- Cerebellar syndrome
What is this physical sign?
Lip telangiectasia
- Hereditary ataxia telangiectasia
