42 Acute Medicine 2014; 13(1): 42-47 Problem-Based Review 42 The Patient with Ataxia saf FG Maggs Abstract In this article we look at the causes of ataxia, and how the patient presenting with ataxia should be managed. One of the difficulties in managing the patient with ataxia is that acute ataxia has many causes, but usually these can be teased out by means of a careful history and examination. Investigations can then be targeted at confirming or disproving the differential diagnosis. Some patients with ataxia need to be managed in hospital, but many can be investigated, and receive therapy, as an outpatient. Keywords Ataxia, Unsteadiness, Coordination, Cerebellum Key points • In the patient presenting with acute ataxia consider cerebellar infarcts, acute intoxication, Miller-Fisher syndrome and Wernicke-Korsakoff syndrome: these diagnoses must not be missed and require urgent management • An MRI scan of the brain is the preferred imaging modality for the cerebellum • Many patients with acute ataxia will need to be admitted, especially if there is a need for ongoing monitoring, or a risk of falls that means the patient would be unsafe at home. However, if an MRI head is normal, and the patient is well, then further investigations could be carried out as an outpatient What is ataxia? (e.g. anticonvulsants). In adults, the most frequent The word ataxia comes from Greek meaning a “lack causes are ischaemic or haemorrhagic strokes in of order”. Ataxia is the manifestation of dysfunction the cerebellum or brain stem, intoxication (such as of the parts of the nervous system that coordinate therapeutic drugs, alcohol, and drugs of abuse), and movement, and is characterised by clumsy and Wernicke-Korsakoff syndrome due to nutritional uncoordinated intentional movement of the limbs, deprivation (usually, but not always, in alcoholic trunk, and cranial muscles. people). Demyelinating lesions such as multiple Ataxia may result from pathology in the sclerosis can also have a rapid onset and, if they cerebellum (cerebellar ataxia), may be due to loss occur in the cerebellum or its connections, present of proprioception as a result of dysfunction of the with acute ataxia. The Miller-Fisher variant form of dorsal columns of the spinal cord (sensory ataxia), Guillain-Barre syndrome should to be considered in or may be due to vestibular dysfunction (vestibular patients presenting with acute ataxia. ataxia). The three types of ataxia have overlapping causes, and therefore can either coexist or occur in Case scenario isolation. A 66 year old retired teacher was referred to the medical take complaining of leg weakness, general malaise and lethargy. What are the causes of ataxia? He described feeling as if his legs could not hold him, and Inherited ataxias may be classified by their mode had to hold onto things to steady himself, but his legs were Fenella G Maggs of inheritance. For example, Wilson’s disease1 not painful, and he did not complain of any numbness or DPhil, MRCP is a recessive gene disorder which results in an sensory loss. Four weeks previously he had been able to play Consultant in Acute inability to properly excrete copper from the body: golf but was now mobile only with two sticks. He described Medicine, Royal United Hospital, Bath accumulation of copper in the nervous system can some weight loss. cause ataxia. Degenerative ataxia is a term used to His past medical history included hypertension, Correspondence: denote ataxia due to cerebellar atrophy of both hypercholesterolaemia and peripheral vascular disease, but F G Maggs genetic and unknown causation. he lived an active and independent life. He was taking Royal United Hospital, The list of acquired causes of ataxia is extensive simvastatin, bendroflumethiazide, felodipine, enalapril Combe Park, Bath. BA1 3NG (Box 1). Age at onset is an important determinant of and aspirin. He was a current smoker, smoking 15 – 20 Email: fgmaggs@doctors. cause. Ataxia of acute onset in a child is most likely to cigarettes per day for 53 years, and drank up to 40 units of net.uk result from acute cerebellitis or may be drug-induced alcohol per week. © 2014 Rila Publications Ltd. Acute Medicine 2014; 13(1): 42-47 43 The Patient with Ataxia Box 1. Causes of acquired ataxia Examples Notes Focal lesions Stroke, tumour, multiple sclerosis Cause the type of ataxia corresponding to the site of the lesion Exogenous substances Alcohol, lithium,2 antiepileptic drugs,3 Lithium level over 1.5mEq/L metronidazole,4 benzodiazepines,5 amiodarone,6 recreational drugs,7 Exposure to high levels of methylmercury solvent poisoning,8 methylmercury9 through consumption of fish with high mercury concentrations Radiation poisoning Acute radiation poisoning with an absorbed dose of more than 30 Grays10 Degenerative causes Alcohol, paraneoplasia, normal Paraneoplastic syndromes: ataxia may appear pressure hydrocephalus, high altitude months or years before the cancer is diagnosed. cerebral oedema, Coeliac disease,11 cerebellitis Cerebellitis usually seen in children Nutritional Vitamin B12 deficiency12 Cerebellar and sensory ataxia Vitamin B1 deficiency 13 Often part of Wernicke-Korsakoff syndrome in alcoholic people and other patients who have severe nutritional deficiency Severe vitamin E deficiency14 Occurs in fat malabsorption Infections Chicken pox15 Ataxia may appear in the healing stages of the infection and last for days or weeks. Normally, the ataxia resolves completely over time. Cerebellar abscess Rapid onset of ataxia with headache; can be a complication of middle ear infections HIV infection16 Progressive ataxia that becomes debilitating over several months; many cases of HIV dementia may exhibit ataxia at onset Prion protein disease can have a predominantly ataxic presentation17 Endocrine Hypothyroidism18 Reversible cerebellar ataxia, dementia, peripheral neuropathy, psychosis and coma. Most of the neurological complications improve completely Hyponatraemia19 after thyroid hormone replacement therapy. Peripheral neuropathy Isolated sensory ataxia On examination he appeared well. He was afebrile, with between light-headedness and vertigo, which are blood pressure 130/65, pulse 72 bpm, respiratory rate 21/ often lumped together as a feeling of ‘dizziness’. A min, and oxygen saturations 98% on air. Cardiovascular, history of vertigo, tinnitus, and hearing problems respiratory and abdominal examinations were unremarkable. may indicate a peripheral vestibular problem, Neurological examination revealed proximal muscle wasting while the presence of speech disturbance and visual but no other abnormal neurology. His gait was ataxic but symptoms suggests cerebellar pathology. Explore there were no other cerebellar signs. symptoms that may indicate increased intracranial pressure (e.g. headache, nausea, vomiting) or What are the vital clues from the problems in structures contiguous to the cerebellum history? (e.g. weakness or sensory problems in the limbs or cranial nerve deficits). Presenting complaint The duration of symptoms may give clues as to Precise questions may need to be asked to be sure the underlying cause: strokes usually present with a what the patient is experiencing. Patients will be short history while a degenerative cause may have a likely to describe ataxia as unsteadiness, a lack of prolonged history. In slow-onset, chronic bilateral balance or giddiness. It is important to distinguish cases of vestibular dysfunction, dysequilibrium may © 2014 Rila Publications Ltd. 44 Acute Medicine 2014; 13(1): 42-47 The Patient with Ataxia be the sole presentation, while acute labyrinthitis differentiate cerebellar ataxia from other types of is usually unilateral and associated with prominent incoordination. vertigo, nausea and vomiting. Co-ordination Systemic enquiry / Past medical history • There is uncontrolled tremor of limbs during Evaluate risk factors for cerebrovascular disease such relatively slow but targeted movements as hypertension and hypercholesterolaemia. Ask • There may also be tremor of the head and about falls: many patients with ataxia may be able trunk (titubation)22 to investigated and managed as outpatients, but a • Inspect for limb dysmetria (lack of coordination history of falls may preclude this. Studies examining typified by the undershoot or overshoot falls in patients with ataxia show that 74-93% of of intended position) by testing finger- patients have fallen at least once in the past year and to-nose, and heel-to-shin, movements,22 up to 60% admit to fear of falling.20,21 Ask about dysdiadokokinesia, and heel-tapping symptoms of hypothyroidism. Determine whether • Check for overshooting with the wrist-tapping there has been any weight loss which may suggest an test, in which the patient is unable to maintain underlying malignancy. postures against an unexpected displacement Speech Drug history • Evaluate the speech for dysarthria and scanning Several prescription drugs can cause ataxia. Most speech. In scanning speech, the volume of the antiepileptic drugs have cerebellar ataxia as a possible patient’s voice varies from low to high22 adverse effect,3 high lithium levels can lead to ataxia,2 • There may also be slurring of speech and and, in high doses, benzodiazepines can cause short tremor of the voice term ataxia.3 Ask about cannabis ingestion and other Eye movements recreational drugs.7 • Examine eye movements for nystagmus, jerkiness on attempted smooth pursuit, and Social history slowed saccades. Oculomotor palsy can be Alcohol causes reversible cerebellar and vestibular