Neurolist Case Study

Asymmetrical Weakness of Proximal Lower Extremities in patient with Multiple Myeloma

65 y/o WM with history of multiple myeloma diagnosed in July 2008 s/p Revlimid treatment and autologous bone marrow transplant c/o worsening pain and progressive weakness of bilateral lower extremities, L > R. Patient states that the symptoms begins roughly 1-2 weeks after his autologous bone marrow transplant 01/09/09. Patient describes the pain as episodic throbbing and aching pain that originates in various positions through out the leg with each episode lasting from hours to day. Patient denied noticing anything that can aggravate the symptoms but noticed that symptoms are often relieved by soaking the area with warm or hot water or resting. Patient has also experienced weakness of bilateral lower extremities concurrent with the pain, but states that the weakness did not bother him as much as the pain did until roughly 2-3 weeks prior to his presentation to the clinic when he noticed worsening of his weakness and sustained a fall because his L knee "gave out". Since then, he has been using a walker to assist him but sustained another fall even with the walker. He was given Neurotin 300mg TID as his symptoms might be due to chemotherapy induced peripheral neuropathy and he states that the medication provided minor relief for his symptom. Patient has sustained a cervical trauma in distant past but denied any residual neurological deficits or cervical or back pain. Patient also denied numbness, tingling, bowel or bladder incontinence, dyspnea, swelling or color change of the lower extremities, or claudication. PMH, PSH, and FM are otherwise noncontributory. Patient is currently taking Percocet PRN, Acyclovir, Temazepam, and Neurotin 300mg TID. Physical exam is significant for 4- strength in proximal LLE and 4+ strength in proximal RLE, decreased vibratory sensation in bilateral toes up to ankle level bilaterally (L > R), and negative Romberg. Laboratory studies, including ESR and CPK, are within normal limits. MRI studies of thoracic and lumbar spine showed degenerative disc disease consistent with patient's age, otherwise no spinal canal stenosis or abnormal enhancements or lesions of the spinal cord are observed. 

              

EMG study showed deminished recruitment and small amplitude waves in L vastus, L adductor longus, iliopsoas, consistent with myopathy. However, L tensor fasciae latae was normal.

Because of patient's symptoms, history of multiple myeloma, and exam findings, it is felt that patient might be experiencing autoimmune related myopathy. However, the possibility of lumbar plexus lesions causing similar exam finding cannot be completely ruled out. As a result, MRI of lumbar plexus with contrast will be ordered. If the MRI result is normal, then muscle biopsy will be performed. Pending the result of muscle biopsy, lumbar puncture may also be performed for evaluation of CSF.