A 15-year-old boy is reviewed. He has been referred by his GP with ptosis, diplopia and night blindness. On examination he is noted to have a degree of ophthalmoplegia, bilateral partial ptosis and evidence of retinitis pigmentosa during fundoscopy. His mother developed a similar problem when she was 18-years-old.
What is the most likely diagnosis?
Correct Answer A:
Mitochondrial diseases:
Whilst most DNA is found in the cell nucleus, a small amount of double-stranded DNA is present in the mitochondria. It encodes protein components of the respiratory chain and some special types of RNA.
Mitochondrial inheritance has the following characteristics:
Histology:
Examples include:
A 34-year-old female with a history of primary generalized epilepsy asks for advice in the neurology clinic as she plans to start a family. She currently takes sodium valproate as monotherapy.
What advice should be given regarding the prevention of neural tube defects?
Correct Answer C: Epilepsy + pregnancy = 5mg folic acid.
Epilepsy: pregnancy and breast feeding:
The risks of uncontrolled epilepsy during pregnancy generally outweigh the risks of medication to the fetus. All women thinking about becoming pregnant should be advised to take folic acid 5mg per day well before pregnancy to minimize the risk of neural tube defects. Around 1-2% of newborns born to non-epileptic mothers have congenital defects. This rises to 3-4% if the mother takes antiepileptic medication.
Other points:
Breast feeding is generally considered safe for mothers taking antiepileptics with the possible exception of the barbiturates.
It is advised that pregnant women taking phenytoin are given vitamin K in the last month of pregnancy to prevent clotting disorders in the newborn.
Which one of the following is least likely to cause a raised protein level in the cerebrospinal fluid?
Correct Answer E:
Cerebrospinal fluid: raised protein:
Normal values of cerebrospinal fluid (CSF) are as follows:
The following conditions are associated with raised protein levels:
*Describes an increase in CSF protein below a spinal canal blockage (e.g. tumour, disc, infection).
Which one of the following features is most associated with parietal lobe lesions?
Brain lesions:
The following neurological disorders/features may allow localization of a brain lesion:
Gross anatomy: Parietal lobe lesions:
Occipital lobe lesions:
Temporal lobe lesion:
Frontal lobes lesions:
Cerebellum lesions:
More specific areas:
You are asked to perform a neurological exam of the lower limbs on a patient with multiple sclerosis.
Which one of the following findings is least typical?
Correct Answer A: In multiple sclerosis there is demyelination of the central nervous system and hence upper motor neuron signs are seen.
Multiple sclerosis: features:
Visual:
Sensory:
Motor:
Cerebellar:
Others:
Click to expand