Table 2.

The clinical manifestations of Hirayama disease with proximal involvement.

No.	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
Age of onset/yrs	17	16	17	16	17.5	17	20	18	20	25	17	16.5	16.5	16	18
Course of illness/yrs	1	0.25	1	8	0.5	3	4	2	5	3	3	0.33	0.5	3	4
Symptom side(s)	Right	Left	Bilateral	Left	Right	Bilateral	Right	Right	Bilateral	Bilateral	Bilateral	Bilateral	Right	Right	Bilateral
Muscle strength
Shoulder abduction	IV	IV	IV	IV	V	V	IV	III	V	V	V	V	IV	V	V
Elbow bend	IV	IV	IV	IV	IV	V	III	IV	IV	V	V	V	IV	V	V
Elbow extension	IV	IV	IV	IV	V	IV	IV	IV	IV	V	V	V	V	V	V
Wrist flexion	IV	IV	V	IV	V	V	IV	V	IV	V	IV	V	V	V	V
Wrist extension	IV	IV	V	IV	V	V	IV	V	IV	V	IV	V	V	V	IV
Grip	IV	IV	V	IV	V	V	III	V	IV	IV	IV	IV	IV	IV	IV
Deep tendon reflex
Biceps reflex	Unknown	Unknown	+	+	+	++	+	+	+	++	++	++	+	+	+++
Triceps reflex	Unknown	Unknown	+	+	++	+	+	+	+	++	++	++	+	+	++
Knee reflex	++	+++	+++	++	+++	++++	++++	++++	++++	++++	++++	++	++	+++	+++
Hoffmann sign	Negative	Negative	Positive	Positive	Positive	Positive	Positive	Positive	Positive	Positive	Positive	Negative	Negative	Negative	Positive

+, Decreased; ++, Normal; +++, Brisk; ++++, Hyperactive.