Holocord abscess in association with congenital dermal sinus.

Intramedullary spinal cord abscess in children is rare and holocord abscess is rarer. An 18-month-old girl presented with rapidly progressive paraplegia with fever for 2 months. The patient had complete flaccid paraplegia with absent sensation below D4 level. There was very small dermal sinus discharging pus in the lower lumbar region. Magnetic resonance imaging showed evidence of extensive multiloculated intramedullary abscess extending from D4 to L5 with cord edema upto cervical level. Laminotomy, excision of the dermal sinus and myelotomy, and evacuation of intramedullary abscess was performed. Escherichia coli and Pseudomonas were grown on culture. The child was treated with long-term parenteral antibiotics and started showing neurological improvement. Holocord abscess secondary to congenital dermal sinus is extremely rare and this is only the fourth report of such an instance.

Introduction

Intramedullary spinal cord abscesses are rare. Only about 100 cases have been reported in the literature, after the first description by Hart in 1830.[12] It is still rarer in children with only about 40 cases occurring in the pediatric age group.[3] Holocord abscess in children is very rare and only three cases are encountered in the literature.[456] It is very important to remember this entity, as it is a curable condition, if detected and treated early.

Case Report

An 18-month-old girl child presented with rapidly progressive bilateral lower limb weakness with fever for 2 months. The mother of the child also noticed that she was not feeling any sensation below the nipples and had bladder incontinence. The fever was intermittent and the child was on several antibiotics without any benefit. Neurological examination showed conscious and active child. She had flaccid paraplegia with grade “0” power with absent deep tendon reflexes. Sensory examination showed absent sensation to pain below D4 level on both sides. Power, tone, and sensation were normal in the upper limbs. There were no signs of meningeal irritation. Careful examination of the back showed a very small dermal sinus in the lower lumbar region, discharging pus on digital pressure. Magnetic resonance imaging (MRI) showed multiple coalescing ring enhancing lesions in the spinal cord extending from D4 to L5 with cord edema upto cervical level [Figure 1]. The differential diagnosis considered were holocord glioma and holocord abscess. Modified osteoplastic laminotomy, described by Raimondi et al.,[7] was performed from D4 to L5 [Figure 2]. The dermal sinus tract was seen to extend from the skin at L5 and end intradurally at the same level. Dura was opened and there was dermoid material and pus in the lumbar region The spinal cord was found to be diffusely enlarged. Myelotomy was performed at different levels and pus was evacuated from the spinal cord [Figure 3]. There were extensive arachnoidal adhesions. In view of the extensive nature of the abscess, no attempt was made to excise the abscess capsule. The dura was closed with fascial graft. The laminotomy flap was replaced [Figure 4]. The child stood the surgery well and the postoperative period was uneventful. Escherichia coli and Pseudomonas aeruginosa were grown on culture. She was started on antibiotics as per the sensitivity report. She started showing some neurological improvement within a few days in the form of some movement in both the legs. She was on long-term antibiotics for 8 weeks and physiotherapy. At 2 months follow-up, she had grade 3 power in the right lower limb and grade 1-2 power in the left. Sensory level was at D12 both sides. Follow-up MRI shows good resolution of the intramedullary abscess [Figure 5].

Figure 1

Pre-operative Magnetic Resonance Imaging (Contrast enhanced T1 weighted sagittal image), showing the multiloculated holocord abscess from cervical to lumbar region

Figure 2

Intra-operative picture showing the dermal sinus tract and osteoplastic laminotomy

Figure 3

Intra-operative picture showing the holocord abscess

Figure 4

Intra-operative picture showing laminotomy closure

Figure 5

Post-operative Magnetic Resonance Imaging (T2 weighted sagittal image), showing complete resolution of the holocord abscess

Discussion

Intramedullary spinal cord abscess is a rare condition. Hart[1] reported the first case of intramedullary spinal cord abscess. Byrne et al.,[8] reviewed the literature and found 75 cases of intramedullary abscess. Thoracolumbar region is the commonest location of the intramedullary abscess.[9] Intramedullary abscess involving the entire length of spinal cord, otherwise called holocord abscess, is still rarer. Very few cases of holocord abscess have been reported in the literature. Congenital dermal sinus is one of the common types of spinal dysraphism. The commonest type of central nervous system infection due to dermal sinus is meningitis. Intramedullary abscess due to congenital dermal sinus is very rare. Only about 16 cases of intramedullary abscess secondary to a dermal sinus have been reported so far.[10] Still rarer is the holocord abscess secondary to congenital dermal sinus. There are only three previous reports of holocord abscess secondary to dermal sinus in the literature.[567]

The first holocord intramedullary abscess secondary to congenital dermal sinus was reported by Bunyaratavej et al.,[4] This patient was a 2-month-old baby presenting with paraplegia with a dermal sinus in the lumbosacral region discharging pus. MRI showed single large intramedullary abscess extending from C1 to conus medullaris and the patient was treated with limited myelotomy in the lumbar region and aspiration through a cephalically advanced feeding tube. The child had recovered completely at 26 months’ follow-up. The second report was by Kalia et al.[5] This was an 18-month-old baby, presenting with fever and progressive paraparesis for 3 months with a lumbosacral pus discharging congenital dermal sinus. MRI showed evidence of intramedullary abscess extending from cervical level to conus. The patient was treated with limited laminectomy and drainage of intramedullary abscess. The pus did not grow any organism. The third report (Kim et al., 2010) was that of a 7-month-old child presenting with fever and rapidly progressive quadriplegia with a dermal sinus in the lumbar region.[6] Spine MRI showed thick irregular ring enhancing lesions extending from high cervical area to L 3 and thickest in mid thoracic region. The patient was treated with lumbar laminectomy with limited myelotomy and evacuation of the abscess. Pus grew Citrobacter freundii on culture. The child started showing recovery by 3 weeks.

It is seen from our case and the previous reports that one has to suspect intramedullary spinal cord abscess in an infant or child presenting with fever and paraparesis or quadriparesis. Careful examination of the back for congenital dermal sinus has to be made in all the cases. MRI finding is diagnostic but may be mimicked by other intramedullary tumors. The treatment is by lumbar laminectomy/laminoplasty and limited myelotomy and evacuation of the abscess in majority of the patients.[10] In our case, we had to perform extensive laminotomy and multiple myelotomies, because of the multiloculated chronic nature of the abscess. We performed osteoplastic laminotomy and fixed it back after myelotomy and evacuation of the abscess and the child has not developed any spinal deformity so far.

Since congenital dermal sinus is the cause for many devastating central nervous system infections including meningitis and spinal cord abscess, this has to be identified and surgically managed before the onset of the above complications. This reemphasizes the need for prophylactic surgery at the earliest in all infants and children with congenital dermal sinus. The present report is only the fourth case of holocord abscess secondary to congenital dermal sinus.