A 31-year-old woman presents to accident and emergency with progressive difficulty walking associated with lower back pain. A few days ago she was tripping over things, now she has difficulty climbing stairs. She describes tingling and numbness in both hands which moved up to her elbows, she is unable to write. On examination, cranial nerves are intact but there is absent sensation to vibration and pin prick in her upper limbs to the elbow and lower limbs to the hip. Power is 3/5 in the ankles and 4−/5 at the hip with absent reflexes and mute plantars. Her blood pressure is 124/85, pulse 68 and sats 98 per cent on air. She has a past medical history of type I diabetes and recently recovered from an episode of food poisoning a month or two ago. What is the diagnosis?
B. Guillain–Barré syndrome (GBS)
C. Myasthenia gravis
D. Diabetic neuropathy
E. Infective neuropathy
Ans=B This woman presents with an ascending polyneuropathy. Her symptoms start distally and progress proximally, giving a glove and stocking distribution. Both sensory and motor neurones are involved. This is consistent with Guillain–Barré (B), an inflammatory disorder of the peripheral nerves often preceded by an infection such as campylobacter gastreoenteritis. Multiple sclerosis (A) is an inflammatory disorder of the central nervous system resulting in upper motor neurone signs – this patient’s reflexes are absent. Myasthenia gravis (C) is a disorder of the
neuromuscular junction and although it results in lower motor neurone signs, there is no sensory involvement and the weakness is greater in proximal muscles and commonly involves the cranial nerves resulting in droopy eyelids, difficulty speaking and swallowing. A key feature is fatigability as the stores of acetylcholine are used up. Although this woman is diabetic and has a polyneuropathy, her symptoms progress too quickly. Diabetic neuropathy (D) takes time to develop and, although there are different types, most commonly results in a distal sensory neuropathy of the feet. Vibration and pain are most affected which is why they may have a stomping gait and develop ulcers. Infective neuropathies (E) include Lyme disease from ticks and leprosy which is uncommon in developed countries and she has no history of travel.