Neurofibromatosis type 1 is associated with a gene defect on which chromosome?
Correct Answer D:
mnemonic:
Neurofibromatosis:
There are two types of neurofibromatosis, NF1 and NF2. Both are inherited in an autosomal dominant fashion.
NF1 is also known as von Recklinghausen's syndrome. It is caused by a gene mutation on chromosome 17 which encodes neurofibromin and affects around 1 in 4,000 NF2 is caused by gene mutation on chromosome 22 and affects around 1 in 100,000
Features:
A 41-year-old man presents with a two week history of headaches around the left side of his face associated with watery eyes. He describes having about two episodes a day each lasting around 30 minutes. On examination he has a red left eye and a partial left ptosis. There is no past medical history of note other than migraines as a child.
What is the likely diagnosis?
Correct Answer B: Episodic eye pain, lacrimation, nasal stuffiness occurring daily - cluster headache.
Cluster headache:
Cluster headaches* are more common in men (5:1) and smokers.
Management:
*Some neurologists use the term trigeminal autonomic cephalgia to group a number of conditions including cluster headache, paroxysmal hemicrania and short-lived unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT). It is recommended such patients are referred for specialist assessment as specific treatment may be required, for example it is known paroxysmal hemicrania responds very well to indomethacin.
A 55-year-old man is referred to the neurology clinic due to a resting tremor and an abnormal gait characterized by short, shuffling steps.
Which one of the following features would point towards a diagnosis of Parkinson's disease rather than parkinsonism of another cause?
Correct Answer A: Asymmetrical symptoms suggests idiopathic Parkinson's.
Parkinson's disease: features:
Parkinson's disease is a progressive neurodegenerative condition caused by degeneration of dopaminergic neurons in the substantia nigra.. This results in a classic triad of features: bradykinesia, tremor and rigidity. The symptoms of Parkinson's disease are characteristically asymmetrical.
Bradykinesia:
Tremor:
Rigidity:
Other characteristic features:
Drug-induced parkinsonism has slightly different features to Parkinson's disease:
A 40-year-old woman presents with recurrent episode of vertigo associated with a feeling or 'fullness' and 'pressure' in her ears. She thinks her hearing is worse during the attacks. Clinical examination is unremarkable.
What is the most likely diagnosis?
Correct Answer A:
Meniere's disease:
Meniere's disease is a disorder of the inner ear of unknown cause. It is characterized by excessive pressure and progressive dilation of the endolymphatic system. It is more common in middle-aged adults but may be seen at any age. Meniere's disease has a similar prevalence in both men and women.
Natural history:
A 64-year-old man presents with a eight-month history of generalized weakness. On examination he has fasciculation and weakness in both arms with absent reflexes. Examination of the lower limbs reveal increased tone and exaggerated reflexes. Sensation was normal and there were no cerebellar signs.
Correct Answer B: 'Fasciculations' - think motor neuron disease.
These symptoms are typical of amyotrophic lateral sclerosis, the most common type of motor neuron disease.
Motor neuron disease: features:
Motor neuron disease is a neurological condition of unknown cause which can present with both upper and lower motor neuron signs. It rarely presents before 40 years and various patterns of disease are recognized including amyotrophic lateral sclerosis, progressive muscular atrophy and bulbar palsy.
There are a number of clues which point towards a diagnosis of motor neuron disease:
Other features:
The diagnosis of motor neuron disease is clinical, but nerve conduction studies will show normal motor conduction and can help exclude a neuropathy. Electromyography shows a reduced number of action potentials with an increased amplitude. MRI is usually performed to exclude the differential diagnosis of cervical cord compression and myelopathy.
*Vague sensory symptoms may occur early in the disease (e.g. limb pain) but 'never' sensory signs.
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