Systemic carnitine deficiency with peripheral nerve involvement morphological and biochemical study.

The patient, a 31-year-old woman, suffered from a weakness of the proximal muscles which subsequently worsened involving the spinal and neck muscles. During the hospitalization, the patient displayed a "burning feet" syndrome. Lab tests showed a moderate increase in CPK, Aldolase, SGPT, SGOT, lactic and pyruvic acids. Needle EMG was interpreted as "myopathic" but a marked reduction of sensitive action potentials was also detected. Muscle biopsy showed neutral lipid accumulation in muscle fibers, many small angular fibers, probably denervated ones were also evident. A liver biopsy showed fatty accumulation in hepatocytes. Free carnitine was extremely reduced in muscle and liver and just below normal level in plasma while there was a tenfold elevation of long-chain carnitine esters in plasma too. The mechanism by which carnitine deficiency can cause both neural and muscular alterations and in particular the role of carnitine in glucose metabolism is discussed.