A 37-year-old woman had problems with numbness, tingling, and weakness on her feet. Symptoms gradually progressed to the point where she became wheelchair bound. She also lost about 60 to 70 pounds.

This 37-year-old woman had a 1-year history of progressive painful numbness and tingling, initially in the feet and legs and subsequently spreading into the hands and face. She had symmetrical distal sensory loss including profound deficits of position and vibratory sense. Muscle stretch reflexes were absent. She had a severe sensory ataxia with a positive Romberg sign. Sural nerve biopsy demonstrated demyelination but no inflammation.

Causes of sensory ataxia include posterior-column myelopathies, sensory ganglionopathies (non-length-dependent proprioceptive and vibratory sensory deprivation), and demyelinating autoimmune polyneuropathies (Table 7.1). Sensory ataxias are not an early manifestation of axonal distal peripheral neuropathies. A considerable number of patients have no identifiable explanation. In our patient, there was a past history of psychiatric disease as well as dramatic weight loss prior to the onset of symptoms. The psychiatric history should raise concerns of a possible toxic exposure, as well as the possibility for an underlying connective tissue disease such as systemic lupus erythematosus (SLE). Our patient had been screened for these conditions with Anti-Hu serology, Anti-Ro
(SSA) cytoplasmic antibodies and Anti-La (SSB) antibodies, cerebrospinal fluid (CSF) for elevated protein (as would be seen with a chronic immune-mediated or inflammatory process), and serum B₁₂ studies, along with blood work and scans searching for occult systemic disease including malignancy. Even though a malignancy was not detected, the patient’s history of cigarette smoking and the lack of objective evidence for inflammation prompted us to remain vigilant with regard to the possibility of malignancy. Spinal cord magnetic resonance imaging (MRI) showed no evidence of T2-high signal abnormalities in the dorsal columns. A positron emission tomography (PET) scan was normal. The patient’s predominantly sensory, symmetric demyelinating polyneuropathy fits best with the distal acquired demyelinating symmetric (DADS) neuropathy variant of chronic inflammatory demyelinating polyneuropathy. Patients often, but not always, demonstrate an IgM monoclonal gammopathy with anti-MAG (myelin-associated glycoprotein) antibodies. Presence of these IgM M-proteins is associated with steroid failure.