Small-nerve-fiber pathology in critical illness documented by serial skin biopsies.

Small-fiber pathology can develop in the acute phase of critical illness and may explain chronic sensory impairment and pain in critical care survivors. Eleven adult ischemic stroke patients in a neurocritical care unit were enrolled in an observational cohort study. Intraepidermal nerve fiber density (IENFD) in the distal leg was assessed on admission to the intensive care unit and 10-14 days later, together with electrophysiological testing. Of the 11 patients recruited, 9 (82%) had sepsis or multiple-organ failure. Median IENFD on admission (5.05 fibers/mm) decreased significantly to 2.18 fibers/mm (P < 0.001), and abnormal IENFD was found in 6 patients (54.5%). Electrodiagnostic signs of large-fiber neuropathy and/or myopathy were found in 6 patients (54.5%), and autonomic dysfunction was found in 2 patients (18.2%). Serial IENFD measurements confirmed the development of small-fiber sensory involvement in the acute phase of critical illness.