|Year : 2020 | Volume
| Issue : 2 | Page : 137-138
Foot drop – Common entity, uncommon aetiology
Rajendra Singh Jain, Yavnika Jain, Tushar Desai, Trilochan Srivastav
Department of Neurology, Sawai Man Singh Hospital and College, Jaipur, Rajasthan, India
|Date of Submission||22-Jul-2020|
|Date of Decision||19-Aug-2020|
|Date of Acceptance||01-Sep-2020|
|Date of Web Publication||3-Feb-2021|
Dr. Yavnika Jain
Department of Neurology, Sawai Man Singh Hospital and College, Jaipur, Rajasthan
Source of Support: None, Conflict of Interest: None
Foot drop is defined as the weakness of the tibialis anterior muscle and is frequently accompanied by weakness of the extensor hallucis longus and extensor digitorum longus. Dural arteriovenous (AV) fistula present mainly as progressive myelopathy, though it can also appear as amalgam of upper and lower motor involvement signs. Digital subtraction angiography is the definitive radiological procedure in the pre-treatment evaluation of vascular malformation. Treatment modalities include surgical resection or angiographically guided embolisation of malformation. We are reporting a case of spinal AV fistula presenting as unilateral foot drop, which showed significant improvement following the neuro-radiological intervention. Here, we report a rare presentation of spinal AV fistula as foot drop, showing good recovery following glue embolisation.
Keywords: Dural arteriovenous fistula, foot drop, glue embolisation
|How to cite this article:|
Jain RS, Jain Y, Desai T, Srivastav T. Foot drop – Common entity, uncommon aetiology. J Cerebrovasc Sci 2020;8:137-8
| Introduction|| |
Spinal vascular malformation is developmental or acquired abnormal direct communication of normal size to enlarged arteries with enlarged tortuous veins, without intervening capillary network. Dural arteriovenous (AV) fistula is the most common variety, presenting as slowly progressive myelopathy.
| Case Report|| |
A 51-year-old male, presented with 3 months history of progressive difficulty in walking as high stepping, in the background of chronic backache and recently diagnosed diabetes without any history of radicular pain, sensory symptoms, bladder-bowel or erectile dysfunction. Vital parameters, general physical examination and examination of other systems were normal. Neurological examination showed decreased tone around the right ankle joint; power was 5/5 around all joints except the right ankle, where dorsiflexors had the Medical Research Council grade 2/5 with weak extensor hallucis longus. Bilateral mute plantars. In deep tendon reflex, bilateral knee jerk was brisk and ankle reflex was absent. Sensory examination showed 50% sensory loss to pinprick at the right lumbar dermatome 4. Straight leg raise was negative. His routine investigations, including haematology, biochemistry, thyroid profile and Vitamin-B12 levels, were normal. Retroviral serology was negative. Blood glucose level was well controlled. Nerve conduction studies showed the axonal affection of bilateral peroneal nerves. MRI spine showed cord oedema with dilated perimedullary vascular channel seen as vascular flow voids from C7 to D8 level without an intramedullary lesion [Figure 1], computerised tomography (CT) angiography spine revealed long segment collection of tortuous vessel channel noted in the posterior part of the spinal cord from C7 to D8 level [Figure 2]. Spinal digital subtraction angiography was done to detect the feeding vessel. Glue embolisation was done. Significant improvement was noted just after the procedure in the form of on table complete resolution of back pain with improvement in the weakness of dorsiflexors of the right foot to MRC grade 3/5, followed by near-total improvement to 4+/5 at 6 months. Imaging repeated after 6 months revealed complete resolution of the lesion [Figure 3].
|Figure 2: Computerised tomography angiography spinal cord showing tortuous dilated vascular channel|
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|Figure 3: Magnetic resonance imaging spine. (a) Pre-embolisation T2 magnetic resonance imaging spine film showing prominent flow voids, (b) post-embolisation film showing absent flow voids|
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| Discussion|| |
Foot drop is defined as the weakness of the tibialis anterior muscle and is frequently accompanied by weakness of the extensor hallucis longus and extensor digitorum longus. Localization of lesion is important to determine whether it is an upper motor neuron lesion or lower motor lesion. Nerve injury is the most common cause of foot drop. Various muscle or nerve disorders with the various brain and spinal cord disorders like ALS, multiple sclerosis or stroke are also implicated. Sengupta et al. reported a case of subdural hematoma presenting with unilateral foot drop. Statin-induced bilateral foot drop was seen in a case of hypothyroidism reported by Neera et al. Spinal Dural AV Fistula is a rare acquired lesion that can impair spinal cord function. These lesions represent the most common type of spinal vascular malformation. Characteristic features of the spinal MRI include multi-levelled T2 hyperintensity in the spinal cord signifying cord oedema and prominent flow voids in the extramedullary and intradural space from venous congestion. Prominent flow voids are commonly mistaken for primary vascular malformation. Flow voids are the consequence of venous congestion and not the site of fistulous shunting. Our case presented with right foot drop on the background of chronic backache. CT angiography revealed tortuous serpiginous vessel bunch extending from C7 to D8.Glue embolisation was done, resulting in on table complete resolution of back pain with improvement in the weakness of dorsiflexors of the right foot to MRC grade 3/5, with near-total improvement to 4+/5 on follow-up at 6 months. Hence, the early diagnosis is the key to success since the symptoms can be reversed if treated before irreversible cord ischaemia or infarction. To the best of our knowledge, this is the rare presentation of spinal AV fistula as foot drop showing good recovery following glue embolisation.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
Daroff RB, Jankovic J, Mazziotta JC, Pomeroy SL. Bradley's neurology in clinical practice e-book. Elsevier Health Sciences; 2015.
Sengupta SK, Bajaj H, Bhattacharya S. Subdural hematoma presenting with unilateral foot drop. Neurology India. 2013;61:199.
Chaudhary N, Duggal AK, Makhija P, Puri V, Khwaja GA. Statin-induced bilateral foot drop in a case of hypothyroidism. Ann Indian Acad Neurol 2015;18:331.
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[Figure 1], [Figure 2], [Figure 3]