A 63-year-old man presented for the evaluation of abnormal gait which began two years before. It developed sub-acutely starting about four weeks after his second unremarkable hip replacement surgery, the first having taken place 8 months earlier. His neurological exam was normal except for the gait (see video). His standing posture was normal but he exhibited hyper-flexion of the knees during ambulation, external rotation of the right leg, abduction of the left leg, excess elevation of the left foot and slightly greater extension of the right lower leg causing a mildly longer stride and asymmetry.
Focal and segmental dystonia following peripheral injury or limb immobilization1,2 is a rare phenomenon, and the very existence of this entity is debated3. Many cases are associated with litigation and other secondary gain, unlike this case, and are thought to possibly represent psychogenic or malingering disorders. The proposed mechanism for “organic” peripheral injury dystonia is aberrant reorganization within the central nervous system secondary to the injury.
A patient with a known history of Neurofibromatosis type I complained of pulsations around her left eye in 2004. The pulsations became more prominent over the years. Her visual acuity is not affected by the pulsations. In addition to the pulsations, she has multiple cutaneous neurofibromas and Lisch nodules on her irides. Although she could feel the pulsations, her vision was not affected.
Pulsatile proptosis in neurofibromatosis is due to progressive dysplasia of the sphenoid wing. Pulsations may be quite pronounced, but the vision is rarely affected. The differential diagnosis of pulsatile proptosis includes Neurofibromatosis type I, carotid cavernous fistula, orbital roof fracture, and arterio-venous malformation. The presence of the characteristic cutaneous findings of neurofibromatosis in this patient along with the characteristic imaging established the diagnosis.
A patient reported bilateral hand tremors when writing but not with other tasks. These "task specific" tremors are considered subcategories of essential tremor. Primary writing tremor, in which the tremor occurs only with writing, is probably the most common. The important teaching point is that the "standard" tremor assessment, watching the patient holding a sustained posture and touching his finger to the examiner's and then back to the nose is not adequate. Patients should be tested doing the activity that causes them the most difficulty.