essential tremor
Medical term for a neurological disorder causing involuntary rhythmic shaking, often in the hands.
Essential tremor is a condition that causes shaking in the hands or head.
振戦 is a general term for tremor, while 本態性振戦 specifically refers to essential tremor, a primary condition without an identifiable cause.
Compound of 本態性 (ほんたいせい, 'essential' or 'idiopathic') and 振戦 (しんせん, 'tremor'). The term is a direct medical translation.