LETTERS TO THE EDITOR
|Year : 2022 | Volume
| Issue : 6 | Page : 1182-1183
Syringomyelia: An unusual cause of pronounced calf hypertrophy
Aparna Kathait, Siddharth Dhar, Divyani Garg, Atri Chatterjee, Shishir K Chandan
Department of Neurology, Vardhman Mahavir Medical College, New Delhi, India
|Date of Submission||01-Jun-2022|
|Date of Decision||14-Jun-2022|
|Date of Acceptance||15-Jun-2022|
|Date of Web Publication||15-Jul-2022|
Department of Neurology, Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi - 110 029
Source of Support: None, Conflict of Interest: None
|How to cite this article:|
Kathait A, Dhar S, Garg D, Chatterjee A, Chandan SK. Syringomyelia: An unusual cause of pronounced calf hypertrophy. Ann Indian Acad Neurol 2022;25:1182-3
Syringomyelia has been uncommonly reported to be associated with upper limb, hand, and even body hypertrophy. A proposed mechanism involves augmented sympathetic outflow leading to increased vascular flow and resultant bone, muscle and tissue hypertrophy. However, the exact mechanism remains unclear, and most of such descriptions are relegated to older case reports.,,,,, We present an extremely rare report of a patient who developed bilateral, asymmetrical, and prominent calf hypertrophy as a result of long-standing syringomyelia.
A 50-year-old male presented with insidious onset and progressive dissociative sensory loss in his right upper limb and right half of upper trunk over the past six years. This was not associated with any motor weakness. For the past 2 years, he had developed urinary hesitancy with interrupted stream. For the past one year, he reported progressive symmetrical proximal lower limb weakness, eventually requiring one-person support to ambulate. He has also noticed progressive increase in the bulk of his lower limbs, left more than right, for the past 2 years. There was no history of trauma or significant family history.
Examination revealed pronounced asymmetric hypertrophy of both lower limbs, striking on the left side, with side-to-side calf difference being 3.5 cm [Figure 1]. His height was 170 cm and weight was 80 kg (BMI = 27.6). He had normal tone and power in both upper limbs. He had spasticity in both lower limbs with power of Medical Research Council (MRC) 4/5 at both hip joints, 4+/5 at both knee joints and 5/5 at both ankle joints. He had diminished reflexes in the right upper limb with brisk lower limb reflexes and extensor plantar response. He had absent pin prick and temperature perception with diminished sensation of touch in right upper limb. Sensation of touch, pain and temperature was decreased in both lower limbs and right half of the trunk. Vibration and joint position sense was relatively preserved. There was no hyperhidrosis or difference in temperature observed between upper and lower limbs.
|Figure 1: (a). Lower limb hypertrophy (left > right). (b). MRI T2 sagittal and (c) axial images showing the presence of diffuse hyperintensity and expansion of central canal from C7 to T9-T10 vertebrae|
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On evaluation, he had normal complete blood count, hepatic, thyroid, and renal function tests with normal vitamin B12 levels. HIV serology was negative. Magnetic resonance imaging of the spine revealed T2/STIR hyperintensity in the central canal from C2-C7 vertebral level displaced towards the right side. From C7-to the level of T9-T10 vertebrae, there was diffuse T2W/STIR hyperintensity and expansion of central canal as well as thinning till L1 vertebral level with no abnormal post contrast enhancement (Supplement). Cerebrospinal fluid (CSF) examination, performed to look for secondary causes of syringomyelia, was acellular, with protein of 36 mg/dL (normal range: 15--45 mg/dL) and glucose of 77 mg/dL (corresponding blood glucose 151 mg/dl, CSF: serum glucose ratio = 0.51). CSF analysis for Gram stain, bacterial culture, Ziehl-Neelsen stain, fungal smear and culture, Gene-Xpert for tuberculosis, cytology for malignant cells was negative. Creatine phosphokinase and lactate dehydrogenase levels were normal. Nerve conduction studies and electromyography of all four limbs were normal. Sympathetic skin response (SSR) was normal. Cold-pressor test performed in both lower limbs was also normal. X rays did not reveal bone hypertrophy. The patient was referred to neurosurgical services for further management.
Syringomyelia is considered to be an extremely uncommon cause of limb hypertrophy. Rare case reports in literature have described the development of hypertrophy mostly in the upper limbs, hand, hemibody distribution or even crossed limb hypertrophy.,,,,, However, there is only one other report of lower limb hypertrophy due to syringomyelia, in association with hypertrophy of the contralateral upper limb. Although atrophy due to damage to motor neurons is the classical observation in syringomyelia, the proposed mechanism underlying the development of hypertrophy is chronic sympathetic overactivity of the preganglionic sympathetic neurons not yet damaged, leading to increased vascular flow, hyperhidrosis and enlargement of bones, muscles and soft tissue., In fact, increased sympathetic tone on the affected limb has been demonstrated in one case report by means of the cold pressor test and SSR. However, we could not demonstrate these in our patient. More advanced autonomic function tests may have revealed corroborative abnormalities. In fact, increased vascular flow bringing in more osteoclasts is believed to underly bone resorption and the development of Charcot's shoulder joint in these patients. Another mechanism has been proposed by Delaporte et al. who reported increased myoblast proliferation in hypertrophic limbs, and speculated that this muscle hypertrophy was due to certain neurotrophic factors released by the spinal cord which were myo-stimulatory.
Another intriguing feature in our patient was asymmetry of hypertrophy. It is possible that stimulated sympathetic neurons were relatively preserved on the more hypertrophic side, although we did not find specific evidence to support this hypothesis in terms of the SSR and cold pressor tests. Although popularly associated with muscle dystrophies, certain neurogenic conditions may also lead to calf hypertrophy. Neurogenic causes of lower extremity hypertrophy include peripheral nerve hyperexcitability syndrome (bilateral), spinal muscle atrophy (bilateral), L5--S1 radiculopathy (unilateral), apart from syringomyelia.
Our case serves to highlight an unusual cause of limb hypertrophy, consequent to a neurogenic condition in the form of syringomyelia, thereby adding to the etiological repertoire.
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Conflicts of interest
There are no conflicts of interest.
| References|| |
Sudo K, Owada Y, Yabe I, Kikuchi S, Tashiro K. Syringomyelia as a cause of body hypertrophy. Lancet 1996;347:1593-5.
Sudarshana Murthy KA, Ravishankar SB. Localized hypertrophy of hand in syringomyelia. J Assoc Physicians India 2001;49:1203-4.
Kita K, Hirayama K, Tokumaru Y, Kijima M. [Chiromegaly in syringomyelia--radiologic studies of hand bones]. Rinsho Shinkeigaku 1994;34:1089-92.
Khanra D, Ray S, Sonthalia N, Talukdar A. Syringomyelia, limb hypertrophy and sympathetic overactivity: A rare association. BMJ Case Rep 2012;2012:bcr0320126092. doi: 10.1136/bcr. 03.2012.6092.
Chakraborty PP, Bandyopadhyay D, Mandal SK, Banerjee R, Chowdhury SR, Majumdar S, et al
. Unilateral limb hypertrophy and shoulder weakness in a 37-year-old woman. Med J Aust 2006;184:130-1.
Mehta J, Khanna S. Syringomyelia as a cause of limb hypertrophy. Neurol India 2002;50:94-6.
] [Full text]
Nambiar M, Onggo JR, Pai V. Neuropathic arthropathy of the shoulder joint secondary to a syringomyelia. BMJ Case Rep 2018;11:bcr-2018-228228. doi: 10.1136/bcr-2018-228228.
Delaporte C, Defer G, Diaz C, Gherardi R, Dautréaux B, Degos JD. Increased growth of myoblasts from hypertrophic muscles in syringomyelia. J Neurol Sci 1991;105:183-91.
Lattanzi S, Cagnetti C, Di Bella P, Scarpelli M, Provinciali L, Silvestrini M. Neurogenic muscle hypertrophy. Neurology 2014;83:2191. doi: 10.1212/WNL.0000000000001048.