Preceding use of neuroleptic (usually develops within two weeks of starting medication)

Agitated delirium progressing to stupor and coma

Generalized ‘lead-pipe’ muscular rigidity, often accompanied by tremor

Temperature >38 °C (may be >40 °C)

Autonomic instability: tachycardia, labile or high blood pressure, tachypnoea, sweating

Typically normal

Typically normal

May show raised protein

Generalized slow wave activity

High creatine kinase (typically >1000 units/L, and proportionate to rigidity)

High white cell count (10–40 × 109/L)

Electrolyte derangements and raised creatinine common

Low serum iron level

Stop neuroleptic

Supportive care

Use benzodiazepine if needed to control agitation

Consider use of dantrolene, bromocriptine or amantadine

Seek expert advice from a neurologist