Hirayama Disease

1. Ade Wijaya, MD – October 2022

2.  Previously known as non-progressive juvenile
spinal muscular atrophy, juvenile muscular
atrophy of the distal upper extremity,
monomelic amyotrophy and juvenile
asymmetric segmental spinal muscular atrophy
 first described by Keizo Hirayama in 1959
 Rare
 M:F = 20:1
 Onset: aged in their teens or twenties
 No clear familial relationship
 Prevalent in Asia, esp. India
Kieser, D.C., Cox, P.J. & Kieser, S.C.J. Hirayama disease. Eur Spine J 27, 1201–1206 (2018).

3.  Insidious onset
 Initially progressive, muscular weakness of the
distal upper limbs
 particularly affecting the strength of the wrist
and fingers with preservation of brachioradialis
 The symptoms are most commonly unilateral,
occasionally bilateral, but asymmetric, and
rarely symmetrically bilateral.
 Over 95% of patients feel that their weakness
worsens in cold environments, termed cold
paraparesis
Hirayama K (2000) Juvenile muscular atrophy of distal upper extremity (Hirayama disease). Int Med 39(4):283–290

4.  progressive muscular wasting and weakness
of the hands and forearms, with preservation
of brachioradialis, giving the characteristic
oblique border of muscular atrophy on both
the volar and dorsal forearms, described as
oblique amyotrophy
 Fasciculations are identifed when the afected
muscles contract, termed contraction
fasciculations
Hirayama K (2008) Juvenile muscular atrophy of unilateral upper extremity (Hirayama disease)—half-century progress and establishment since its discovery. Brain Nerve 60(1):17–29

5.  MRI in full cervical fexion
 Classic crescent-shaped lesion with high
signal intensity onT1 andT2 images in the
posterior epidural space, thought to
represent dilation and congestion of the
posterior internal vertebral venous plexus
Pradhan S, Gupta RK (1997) Magnetic resonance imaging in juvenile asymmetric segmental spinal muscular atrophy. J Neurol Sci 146(2):133–138
Hirayama K, Tokumaru Y (2000) Cervical dural sac and spinal cord in juvenile muscular atrophy of distal upper extremity. Neurology 54(10):1922–1926 7. Tokumaru Y, Hirayama K (1989)
Anterior shift of posterior lower cervical dura mater in patients with juvenile muscular atrophy of unilateral upper extremity. Clin Neurol 29:1237–1243

6.  CT myelogram with the neck in the neutral
position reveals mild to moderate atrophy of
the lower cervical cord in 88% of patients
 Furthermore, anterior displacement of the
spinal cord with antero-posterior fattening of
the cord in neck fexion is seen in 88% of
patients with myelography and 94% of
patients with CT myelography
Hirayama K, Tokumaru Y (2000) Cervical dural sac and spinal cord in juvenile muscular atrophy of distal upper extremity. Neurology 54(10):1922–1926 7. Tokumaru Y, Hirayama K (1989)

7.  Nerve conduction studies, muscle biopsy and
cerebrospinal fuid (CSF) analysis may be used
to exclude other conditions
 Electrophysiology: denervation
 Muscle biopsy: atrophic changes and
evidence of reinnervation with clusters of
small angular fbres and large type groupings
 CSF biochemical analysis is usually normal,
but may show a mild increase in the protein
content (40–60 mg/dl; normal
Kieser, D.C., Cox, P.J. & Kieser, S.C.J. Hirayama disease. Eur Spine J 27, 1201–1206 (2018).

8.  Motor neuron disease
 Spinal muscular atrophy
 Spinal cord infarct
 Tephromalacie anterieur
Hirayama K (2008) Juvenile muscular atrophy of unilateral upper extremity (Hirayama disease)—half-century progress and establishment since its discovery. Brain Nerve 60(1):17–29
Elsheikh B, Kissel JT, Christoforidis G et al (2009) Juvenile muscular atrophy of the distal arm “Hirayama disease”. Muscle Nerve 40(2):206–212

9.  Cervical collar to prevent neck fexion
 Surgical
 The disease is most commonly self-limiting with spontaneous
arrest after initial progression of up to 6 years
 The forward displacement of the dural sac and tightening of the
spinal cord seen on the fexion MRI reduces with time and
corresponds to the clinical course of the disease
 Over 60% of patients will show spontaneous arrest of progression
within 3 years and 85% within 5 years of diagnosis
 With a cervical collar to prevent neck fexion, most will cease
progression and some may improve muscular strength and
resolution of cold paraparesis
Hirayama K (2000) Juvenile muscular atrophy of distal upper extremity (Hirayama disease). Int Med 39(4):283–290
Tashiro K, Kikuchi S, Itoyama Y et al (2006) Nationwide survey of juvenile muscular atrophy of distal upper extremity (Hirayama disease) in Japan. Amyotroph Lateral Scler 7(1):38–45
Tokumaru Y, Hirayama K (1992) A cervical collar therapy for nonprogressive juvenile spinal muscular atrophy of the distal upper limb (Hirayama’s disease). Clin Neurol 32:1102–1106

10.  Rare, more common in male in teens or twenties
 Asymmetric progressive, muscular weakness of
the distal upper limbs affecting wrist and fingers
 Muscular wasting, weakness, fasciculations
 Investigation: MRI in full cervical flexion
 Treatment: Cervical collar to prevent neck fexion
& Surgical
 The disease is most commonly self-limiting with
spontaneous arrest after initial progression of up
to 6 years