The cerebellum can be divided into central structures (lingula, vermis and flocculonodular lobe) and the cerebellar hemispheres. Main inputs come from frontopontocerebellar connections (contralateral) from above, and spinocerebellar tracts from below (proprioception) producing primarily ipsilateral signs.
Midline lesions can produce severe gait and truncal ataxia. As they extend they can also give fourth cranial nerve lesions and severe ipsilateral arm tremor, marked nystagmus, vertigo and vomiting, and can block CSF flow (obstructive hydrocephalus).
Cerebellar hemisphere lesions can produce classic ipsilateral limb ataxia (intention tremor, past pointing and mild hypotonia). Limb rebound can be demonstrated by gently pushing down on outstretched arms and then suddenly releasing, causing the arm on the affected side to suddenly fly upwards. Lateral lesions tend to produce more subtle nystagmus (maximal looking towards side of lesion).
See related article Cerebellar Signs including Cerebellar Ataxia.
Note: lesions in the frontal lobe can produce "pseudocerebellar signs" because of the way the frontal lobe influences the cerebellum and basal ganglia.
- Vascular: stroke or transient ischaemic attack (TIA)
- Usually with other brainstem features
- Infarction of the posterior inferior cerebellar artery causes lateral medullary syndrome (Wallenberg's syndrome) with hemiataxia, vertigo, dysarthria, ptosis and miosis
- Posterior fossa tumours or abscess
- Thiamine deficiency - Wernicke's encephalopathy (triad of acute confusion, ataxia and ophthalmoplegia); requires urgent thiamine treatment
- Vitamin E deficiency (including a genetic form)
- Gluten sensitivity (gluten ataxia):
- Neurological dysfunction can be the only manifestation of coeliac disease and, in this situation, typically presents as cerebellar ataxia, ± peripheral neuropathy
- Intestinal symptoms and histological changes may be absent
- The neurological features may reverse with gluten-free diet
- Zinc deficiency (rarely)
- Bacterial: meningo-encephalitis or intracranial abscess
- Viral: acute infections (eg varicella); chronic infections, eg human immunodeficiency virus (HIV); post-viral syndromes (eg postinfective cerebellar syndrome in childhood)
- Parasitic infections (eg toxoplasma, falciparum malaria, Lyme disease)
- Prions: Creutzfeldt-Jakob disease (CJD), kuru
- Toxins: alcohol, mercury, other heavy metals, solvents, carbon monoxide poisoning
- Drugs: barbiturates, phenytoin, piperazine, antineoplastic drugs, deferiprone
- Multiple sclerosis (MS)
- Paraneoplastic cerebellar degeneration:
- This is cerebellar disease occurring with cancer, but not due to brain secondaries; it may be related to antibodies
- It can occur with any cancer but most commonly with lung, gynaecological or breast cancer and Hodgkin's lymphoma
- Genetic: there are a number of inherited cerebellar ataxias:
- Many of these present in adulthood
- Examples are Friedreich's ataxia (the commonest) and ataxia telangiectasia
- Metabolic and endocrine:
- Cerebral oedema of chronic hypoxia
- Wilson's disease (rare)
- Hypothyroidism (rarely)
- Inherited metabolic disorders, eg Leigh’s disease and the mitochondrial disorders
- Developmental anomalies, eg cerebellar hypoplasia, Dandy-Walker syndrome, Arnold-Chiari malformation
- Cerebral palsy
- There are various other uncommon neurological or metabolic diseases which may involve the cerebellum
- Idiopathic cerebellar ataxia - a diagnosis of exclusion
As the cerebellum is associated with motor control, lesions produce a range of movement disorders (ataxias). These can be differentiated by their time course.
Acute onset ataxia
- Either due to cerebellar haemorrhage or infarction. Haemorrhage presents with:
- Occipital headache
- Altered consciousness
May occur from:
- Viral infection - children aged 2-10 years; present with pyrexia, limb and gait ataxia, dysarthria appearing over hours or days; takes up to six months for full recovery
- Post-infectious encephalomyelitis - commonly related to varicella infection but other organisms may be involved
- Other causes include - hydrocephalus, posterior fossa tumours, abscesses, parasitic infections and various toxins
This is episodes of ataxia lasting minutes to hours. May appear bizarre and may be misdiagnosed as being of hysterical origin. There are various causes:
- Transient vertebrobasilar ischaemic attacks
- Foramen magnum compression
- Inherited periodic ataxia, dysarthria, nystagmus and vertigo
- Intermittent obstruction of ventricular system of which there are two types:
- Brief attacks which may benefit from acetazolamide or phenytoin and the patient is usually well between attacks.
- More prolonged attacks which are often associated with nausea, vertigo and vomiting. More severe in childhood with drowsiness, headache and fever and interictal nystagmus; slow deterioration in the ataxia and responds to acetazolamide (screen for metabolic disorder).
Chronic progressive ataxias
- Commonly caused by chronic alcohol abuse associated with malnutrition
- May improve with thiamine
- May also occur with other deficiencies, including zinc and vitamin E
- Other causes:
- Ingestion of drugs - especially anticonvulsants, particularly phenytoin (may reverse once drug stopped)
- Solvent abuse
- Heavy metals
- Structural lesions
- Paraneoplastic cerebellar degeneration associated with carcinomas of the lung or ovaries
- CJD (rare)
Cerebellar disorders in infants
- Initially will only present with non-specific motor development problems
- Later develop nystagmus, incoordination and truncal ataxia on attempting to sit
- Often associated with mental retardation
- Non-progressive and coordination usually improves with age
- Other causes include:
These should be guided according to the differential diagnosis based upon the initial assessment. This may include:
- Blood tests - full blood count, liver function tests, cholesterol, protein electrophoresis, copper and caeruloplasmin, immunoglobulins and glycoproteins
- Imaging - MRI is the modality of choice
Management and prognosis
This depends upon the underlying cause.
Further reading & references
- Patten J; Neurological Differential Diagnosis, 2nd Ed, Springer 1996, IBSN 3-540-19937-3
- Kumar P, Clarke M; Clinical Medicine, 6th Ed, (2005). WB Saunders: London
- National Guideline Clearinghouse: Ataxia. A guideline developed by the American College of Radiology. Revised 2006; Has a useful aetiology section in the second half of the article.
- Wood, N. Ataxic disorders. In: chapter 24.98. Oxford Textbook of Medicine, 3rd Ed, OUP.
- Ataxia.org.uk; Cerebellar ataxia. A guide for the medical profession.
- Hadjivassiliou M, Grunewald RA, Davies-Jones GA; Gluten sensitivity: a many headed hydra. BMJ. 1999 Jun 26;318(7200):1710-1.
- Beau-Salinas F, Guitteny MA, Donadieu J, et al; High doses of deferiprone may be associated with cerebellar syndrome. BMJ. 2009 Jan 22;338:a2319. doi: 10.1136/bmj.a2319.
- Ebersbach G, Sojer M, Valldeoriola F, et al; Comparative analysis of gait in Parkinson's disease, cerebellar ataxia and subcortical arteriosclerotic encephalopathy. Brain. 1999 Jul;122 ( Pt 7):1349-55.
- Steinlin M, Styger M, Boltshauser E; Cognitive impairments in patients with congenital nonprogressive cerebellar ataxia. Neurology. 1999 Sep 22;53(5):966-73.
- Ramaekers VT, Heimann G, Reul J, et al; Genetic disorders and cerebellar structural abnormalities in childhood. Brain. 1997 Oct;120 ( Pt 10):1739-51.
|Original Author: Dr Gurvinder Rull||Current Version: Dr Huw Thomas|
|Last Checked: 18/11/2009||Document ID: 2972 Version: 21||© EMIS|
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