Progressive proximal limb muscle weakness

Characteristically improves with exercise (c.f. myasthenia gravis)

Also develop dry mouth and constipation due to autonomic disturbance

Reflexes are reduced but increase with exertion

Associated with small cell lung carcinoma

Due to an antibody against voltage gated calcium channels resulting in impaired acetylcholine release at the neuromuscular junction

Investigations:

EMG shows increment of evoked muscle action potential (again opposite to that seen in myasthena gravis)

Treatment

Remove tumour

Steroids

Plasma exchange if severe

Diaminopyridine can be useful in chronic cases

Rare

Organic disorder of basal ganglia

Multiple tics

Explosive barking and utterances

Usually Sexual in nature with obscene gestures

More common in males

Develops in childhood

Treatment with Haloperidol may be useful

Common

Autosomal dominant

Affects 2-7% of population

Deficient Bilirubin Glucoronidase

Leads to unconjugated hyperbilirubinaemia

Features

Worse if fasting, unwell or taking alcohol

Investigations

Bilirubin typically 17-85

Other LFT are normal

Management

No treatment needed

Diagnosed on <400cal diet for 24 hours

Aminoaciduria

Can be congenital or acquired

Acquired causes include:                   

Heavy metal poisoning (lead and cadmium)

• Renal disease
• Cystinosis
• Myeloma
• Wilson’s
• Old tetracycline

Defective reabsorption of:  

• Amino acids
• Glucose
• Urate
• Phosphate
• Bicarbonate

Along with:

• K loss
• Polyuria

Juvenile form (De Toni-Fanconi-Debre syndrome) leads to: 

• failure to thrive
• Vomiting
• Thirst
• Vit D resistant rickets

Adult form classically causes Osteomalacia

Treat with vitamin D and electrolyte replacement