An autopsy case of neuroleptic malignant syndrome (NMS) and its immunohistochemical findings of muscle-associated proteins and mitochondria

Neuroleptic malignant syndrome (NMS) is a rare but potentially fatal disord er. In forensic cases, post-mortem diagnosis of NMS is sometimes difficult if ante-mortem information, such as neuroleptic ingestion or signs and symp toms, cannot be obtained. A 39-year-old Japanese male on a neuroleptic trea tment regimen suddenly became agitated and died. Autopsy revealed muscle ri gidity and hyperthermia. Post-mortem examination of blood revealed elevatio n of creatine phosphokinase-MM (CK-MM) and lactate dehydrogenase-4 and dehy drogenase-5 (LDH-4 and LDH-5). In renal glomeruli and tubules, myoglobin wa s stained immunohistochemically. From these findings, the cause of death wa s considered to be NMS. To support the diagnosis of NMS, both skeletal and cardiac muscles were stained with actin, myoglobin, desmin and mitochondria antibodies immunohistochemically. Actin, myoglobin, desmin, and mitochondr ia had been lost from skeletal, but not from the cardiac muscle, which sugg ested that only the skeletal muscle was damaged. Moreover, because mitochon dria had disappeared only from the skeletal muscle, it was considered that skeletal muscle degeneration was caused by mitochondrial damage. Therefore, it is suggested that immunostaining of skeletal muscle by antibodies for m uscle-associated proteins and mitochondria is useful to corroborate a diagn osis of NMS. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.