뿸 10444, 국민건강보험공단 일산병원 재활의학과

VOL. 15, NO. 1, 2016

CLINICAL PAIN 35 접수일 _{: 2015} 년 ₁₀ 월 ₁₂ 일 _, 게재승인일 _{: 2016} 년 ₅ 월 ₂₀ 일

책임저자 _: 김형섭 _, 경기도 고양시 일산동구 일산로 _{100 (} 백석 ₁ 동 1232 번지 ₎

뿸 10444, 국민건강보험공단 일산병원 재활의학과

Tel: 031-900-0670, Fax: 031-900-0049 E-mail: [email protected]

허리 엉치 신경근병증으로 오진한 성인에서 발생한 원발성의 국소성 근긴장이상증을 보튤리늄 주사로 치료한 임상보고 2례

한도병원 재활의학과

, 세브란스병원 재활의학과

, 아주대병원 재활의학과

, 국민건강보험공단 일산병원 재활의학과

홍지성¹ㆍ하다솔²ㆍ이진형²ㆍ박은지³ㆍ김형섭⁴

Adult-onset Primary Focal Foot Dystonia Misdiagnosed as Lumbosacral Radiculo- pathy Treated with Botulinum Toxin Injection

빲

Ji Seong Hong, M.D.

, Da Sol Ha, M.D.

, Jin Hyung Lee, M.D.

, Eun Ji Park, M.D.

and Hyoung Seop Kim, M.D.

1

Department of Physical Medicine and Rehabilitation, Hando Hospital, Ansan,

Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul,

Department of Physical Medicine and Rehabilitation, Ajou University College of Medicine, Suwon,

4

Department and Research Institute of Rehabilitation Medicine, National Health Insurance Service Ilsan Hospital, Goyang, Korea

Adult type dystonia could be easily misdiagnosed as radi- culopathy or other diseases. In these situations the patient could get wrong treatments or even take surgery which could lead to severe complications. This two case report study shows a successful response to Botulinum toxin in- jection in a case of misdiagnosed as radiculopathy which took surgery but had no effect on pain or weakness. Focal foot dystonia is rare but careful observation and physical examination can allow one to avoid unnecessary inter- ventions and could be treated with simple Botulinum toxin injection. (Clinical Pain 2016;15:35-37)

Key Words: Dystonia, Focal, Lower extremity

INTRODUCTION

Dystonia is a syndrome characterized by involuntary un- wanted muscle contractions and abnormal postures.

Dysto- nia of adult-onset usually affects the upper limbs or cranio- cervical regions, but lower extremity dystonia has rarely been reported in adults.

In contrast to childhood-onset dys- tonia, adult-onset lower extremity dystonia usually begins in the foot or leg including foot torsion. Inversion of the foot at the ankle joint is accompanied by flexion of the forefoot and toes. This is often associated with parkinson- ism, stroke, trauma, or psychogenicity, however, several case reports have presented unusual task-specific dystonia triggered by ambulation. Here, we present the two cases of adult-onset primary focal foot dystonia misdiagnosed as lumbar or lumbosacral radiculopathy and treated with botu- linum toxin injection. The aim of this report is proper un- derstanding of this disease and suggesting Botulinum toxin injection a treatment option for adult-onset focal foot dystonia.

CASE REPORT 1. Case 1

A 74-year-old female was initially evaluated on September 4th, 2009 for involuntary posturing of the right foot with clawing of all five toes (Fig. 1). Flexion of toes on the right foot which aggravated on ambulation had start- ed to occur about 10 years ago. One year after the symp- toms appeared, she underwent corrective surgery of the right Hallux Valgus, and 3 years afterwards, decompression and posterior fusion for L3/4, L4/5 and L5/S1 was done.

However there was no improvement of the foot dystonia.

There were no remarkable lesions on brain MRI. Symptom aggravation was triggered by walking and subsided on rest.

Medication such as gabapentin was prescribed but with on-

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CLINICAL PAIN 36

Fig. 1. (A) Flexion of left toes at gaiting due to dystonia. (B) Left side foot dystnoia made his left shoe more ragged than right

side.

ly limited effect on dystonia-related pain.

On May 15th, 2012, she visited our rehabilitation clinic for involuntary flexion of the toes and pain at right foot which resulted in an inability to walk even for short distances. On physical examination, toe clawing and mild inversion of the right foot were observed after few steps of ambulation. There was no diurnal variation. Symptoms became more noticeable with consecutive steps and there- fore walking was limited to about 10 meters.

The patient received Botulinum toxin injections under EMG guidance at the right flexor digitorum brevis (30 unit), flexor digitorum longus (80 unit), flexor hallucis lon- gus (50 unit) and tibialis posterior (40 unit) muscles. On follow-up after 1 week, response to the injection was suc- cessful and she had not experienced hyperflexion of the toes since 2 years, and there was improvement of gait to about a few hundred meters without rest.

2. Case 2

A 65-year-old female noticed toe clawing and pain of her left foot whenever she walked and that had started to occur about 30 years prior to visit our clinic. There were no abnormal movements elsewhere. She had never been on any neuroleptic or dopaminergic drugs and there was no family history of neurological disease. There were no re- markable lesions on brain MRI. About 13 years ago, she had lower back pain with left lower extremity weakness es- pecially on left ankle dorsiflexor and had operation of de-

compressive laminectomy foraminectomy and postero- lateral fusion for L3/4, L4/5 due to impression of Herniated Lumbar Disc. At that time, electrophysiological studies were done and findings were suggestive of left sciatic nerve lesion/lumbosacral plexus lesion and left lumbosacral radiculopathy (mainly L5, S1, S2). After operation, her lower back pain improved, however, there were no im- provement of left leg weakness and spasmodic twisting of the left foot. On June 26th, 2012, she visited our re- habilitation clinic for limping when walking and left toe clawing with left foot inversion. The patient received Botulinum toxin injections under EMG guidance at the right flexor digitorum brevis (40 unit), flexor digitorum longus (70 unit) and flexor hallucis longus (70 unit) muscles. On follow-up after 2 weeks, response to the in- jection was successful and she had not experienced hyper- flexion of the toes since 2 years, and there was an improve- ment of gait to about a few hundred meters without rest.

DISCUSSION

Focal dystonia is a syndrome characterized by in- voluntary tonic or clonic, repetitive muscle contractions.

This case report study documents a successful response to

Botulinum toxin injection in a case of misdiagnosed as rad-

iculopathy which took surgery but had no effect on pain

or weakness. A common disease for a person to have a

consistent flexing toe would be a hyperactive Babinski re-

홍지성 외 4인: 허리 엉치 신경근병증으로 오진된 국소성 근긴장이상증의 보튤리눔 주사 치료 임상보고 2례

CLINICAL PAIN 37 sponse after upper motor neuron injury.

However, in our

case, the Babinski response was not positive on physical examination and there were no other signs of upper motor neuron injury. Two patients in our case reports had no re- markable medical histories; none signs of psychogenic be- havior such as fixed dystonia, inconsistency or brain injury.

The pathophysiology of this dystonia is unclear, and like most other dystonias, it is the result by both genetic and environmental factors.

In other studies it reports that it is generally thought to involve pathology in the brain stem, basal ganglia or local muscle.

Oral medications such as baclofen, diazepam,and dan- trolene have proved unsatisfactory in providing complete symptomatic relief.

Botulinum toxin is the biologic toxin found in nature.

Its pharmacological action is to inhibit acetylcholine release at the neuromuscular junction mem- brane. Botulinum toxin injection function as to release ab- normal contracting muscles which is popular in cosmetic industries.

Botulinum toxin injection is commonly also used widely in Rehabilitation department such as spastic cerebral palsy patients to relive spastic conditions or to im- prove gait patterns in hemiplegic patients.

As Radiculopathy could be easily first suspected in con- ditions as lower extremity pain and weakness; physicians should be aware of other diseases also.

Abnormal posture with involuntary flexion muscles is a important sign of fo- cal dystonia.

In our case by correcting abnormal toe pos- ture with Botulinum toxin injection, our patients were able to achieve improved function. The injection of Botulium toxin was able to safely and effectively relieve persistent focal dystonia who had pain and functional impairment.

Our report supports the curative effect of botulinum toxin injection on primary isolated foot dystonia in an adult.

Although focal foot dystonia is rare, careful observation and physical examination can allow for one to avoid un- necessary interventions or treatments and provide sufficient patients satisfaction.

REFERENCES

1. Ramdhani RA, Frucht SJ. Adult-onset Idiopathic Focal Lower Extremity Dystonia: A Rare Task-Specific Dystonia.

Tremor Other Hyperkinet Mov (N Y) 2013; 3

2. Blunt SB, Richards PG, Khalil N. Foot dystonia and lumbar canal stenosis. Mov Disord 1996; 11: 723-725

3. Young RR. Spasticity: a review. Neurology 1994; 44:

S12-20

4. Hallett M. Neurophysiology of dystonia: The role of inhibition. Neurobiol Dis 2011; 42: 177-184

5. Wissel J, Poewe W. Dystonia--a clinical, neuropathological and therapeutic review. J Neural Transm Suppl 1992; 38:

91-104

6. Ramirez-Castaneda J, Jankovic J. Long-term efficacy and safety of botulinum toxin injections in dystonia. Toxins (Basel) 2013; 5: 249-266

7. Hallett M, Albanese A, Dressler D, Segal KR, Simpson DM, Truong D, et al. Evidence-based review and assessment of botulinum neurotoxin for the treatment of movement disorders. Toxicon 2013; 67: 94-114

8. De Luigi AJ, Fitzpatrick KF. Physical examination in radiculopathy. Phys Med Rehabil Clin N Am 2011; 22: 7-40 9. Singer C, Papapetropoulos S. Adult-onset primary focal foot

dystonia. Parkinsonism Relat Disord 2006; 12: 57-60