An Acute Evolving Flaccid Quadriparesis in an Elderly Woman

A 72-year-old woman was admitted with progressive lower limb weakness, such that she was unable to stand or walk. She was previously healthy, accustomed to play tennis twice a week. Five days prior to admission she had developed low back pain radiating to the legs without a history of trauma. The pain was followed by numbness in the legs, beginning distally and then ascending over two or three days. The patient also experienced weakness that became progressively worse, initially making it difficult to climb stairs and then to walk and stand. Although she had no difficulty passing urine, she did complain of impaired sensation of bladder filling. She had noted some difficulty picking up objects with her hands but had no complaint of upper limb numbness or weakness at the time of admission. Eighteen months earlier she had been diagnosed with diabetes mellitus, which was controlled with diet and an oral hypoglycaemic agent. There was a long-standing history of hypertension controlled with valsartan and felodipine. There was no recent history of travel overseas. No similar clinical problems were known in close family or friends. General medical examination at the time of admission was unremarkable, aside from a palpable bladder, and she was apyrexial. Examination of the nervous system showed the cranial nerves to be intact. Upper limbs were normal in tone, but the lower limbs were flaccid. Weakness was evident, the pattern being more severe in the legs with greater distal than proximal involvement. Medical Research Council muscle power grade (out of 5) was 2 distally, 3–4 proximally in the arms and 1 distally, 2 proximally in the legs. Tendon reflexes were absent throughout. Sensory examination showed reduction in pin-prick sensation to the knees and vibration sensation to the costal margins, and impaired distal proprioception. The patient had an acute evolving neurological syndrome with largely symmetrical sensorimotor dysfunction, with greater motor involvement causing an areflexic flaccid quadriparesis, the temporal and spatial pattern of which was ascending from lower to upper and from distal to proximal in the limbs. The differential diagnosis of this picture is potentially broad (Box 1), encompassing myelopathies, polyneuropathies, neuromuscular transmission disorders, and myopathies, although many of these possibilities are rapidly excluded on the basis of the clinical features. An acute myelopathy such as cord compression or transverse myelitis may present with quadriparesis with, at least in the acute phase, hypotonia and depressed reflexes (i.e., a lower …