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Isolated spinal cord lipoma
Case report
Isolated spinal cord lipoma R. Pathi1 MBBS (HONS) ADEL, M. Kiley2 MBBS FRACP, M. Sage3 MD FRANZCR FRCR FRCP(ED) FRCP(LON) FHKCR(HON) 1 Department of Medical Imaging, Flinders Medical Centre, Bedford Park, SA, Australia, 2Department of Neurology, Royal Adelaide Hospital, SA, Australia, 3 Department of Medical Imaging, Flinders Medical Centre, Bedford Park, SA, Australia
Summary A case of isolated intradural spinal cord lipoma is presented. Most isolated spinal cord lipomas are intradural extramedullary, and the most common location is subpial. True intramedullary lipomas are very rare. Patient history is usually of months to years of local back pain, with recent escalation of pain and development of neurological symptoms. MRI examination shows a well circumscribed lesion of high signal on both T1 and T2 weighted images, and suppression on fat saturation sequence. Subtotal resection is the surgical aim. This improves pain but neurological symptoms rarely improve, usually are unchanged, and occasionally are worse. ª 2003 Elsevier Ltd. All rights reserved. Journal of Clinical Neuroscience (2003) 10(6), 692–694 0967-5868/$ - see front matter ª 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2003.01.001
Keywords: spinal cord lipoma, intradural Received 28 December 2002 Accepted 18 January 2003 Correspondence to: Dr. Ramon Pathi, Department of Radiology, Queen Elizabeth Hospital, Woodville, SA 5011, Australia. Tel.: +61-8-82045855; Fax: +61-8-82043091.
INTRODUCTION Although lipomas of the spinal cord associated with spinal dysraphism are not infrequent, isolated spinal cord lipomas in the absence of such congenital abnormalities are rare. CASE REPORT A 28-year-old man presented for assessment of back pain and weakness of the left leg. At the age of 18 he developed persistent mid-thoracic back pain, which was only partially alleviated by physiotherapy. Over the 12 months prior to presentation his pain progressively worsened. In addition, he had noted that over recent years his left leg appeared smaller than his right leg and his left knee had a tendency to spontaneously give way. He complained of “impaired sensation” over the left foot, stating that when riding his motorbike he had to look down at his foot to ensure that it was on the pedal. On closer questioning he also described a non-specific alteration of sensation of the right leg. Bladder and bowel function was normal and there were no symptoms referable to the upper limbs. Neurological examination revealed normal cranial nerves and upper limbs. On inspection his left leg was smaller than the right, but without evidence of muscle wasting. There was hypertonia with sustained clonus, hyperreflexia and pyramidal weakness on the left. Joint position was markedly impaired on 692
the left with errors at both the toes and ankles, and spinothalamic sensation was reduced over the right leg and trunk up to the level of T6-7. The clinical presentation was consistent with a lesion of the left mid thoracic spinal cord, giving rise to a hemi-cord syndrome (Brown-Sequard Syndrome). The patient therefore went on to have an MRI of his thoracic spine which showed a well defined ovoid lesion at the T2/3 level of both high T1 and T2 signal intensity (Figs. 1, 2, 4 and 5), with suppression on the fat saturation sequence (Fig. 3). There was mass effect and displacement of the cord. The spinal canal was mildly dilated at this level, without extension through neural foramen. He subsequently underwent incomplete surgical resection of the lesion and post-operatively noted subjective improvement, though there was little objective change noted in the immediate post-operative period. Pathological examination of the lesion confirmed a lipomatous tumour. DISCUSSION The first ever report of an intradural lipoma was by Gowers in 1897.1 Lipomas of the spinal cord are most frequent in association with spina bifida (lipomyelomeningocoele). These are more commonly located in the lumbosacral or cervical region, and it is thought this relates to the last sites of closure of the embryonic neural arch, with abnormal inclusion of adipose tissue within the closing lips of the neural groove.2 On the other hand, spinal cord lipomas not associated with spinal dysraphism are rare and make up less than 1% of all spinal cord tumours. There are many reports of extradural lipomas, or intradural extramedullary lipomas, but true intramedullary lipomas are exceedingly infrequent. The common intradural location is subpial.5 Spinal cord lipomas seem to have a peak presentation between 10 and 40 years, with a slight male preponderance. The usual presentation is of a long indolent history, followed by a dramatic worsening over months. All patients describe local back pain in the region of the lipoma, without radicular pain. Paraparesis, sensory disturbance, gait difficulties, incoordination, urinary incontinence, and impotence have all been described.3;4 One or more of these is always present and may prompt the patient to seek medical attention. It is postulated that slow growth of the lipoma allows accommodation within the spinal canal without compromise of function, until a point is reached where further growth causes a rapid decline in function.3 Plain radiographs can frequently be normal, but sometimes may show widening of the spinal canal, scalloping of the vertebral bodies, or destruction of the pedicle.4 These findings can indicate a mass lesion, but are not specific for lipoma. Myelography is now rarely performed but will show a complete or partial block in the flow of contrast within the subarachnoid space.2 Computed tomography can demonstrate a low-density lesion within the spinal cord, but MRI is diagnostic for lipoma.3 Lesions show high signal on T1-weighted images, and decreased signal intensity on T2-weighted images. The lipoma is well defined from surrounding cord tissue, and usually ovoid in the longitudinal axis of the cord. There is no enhancement on administration of gadolinium, while signal intensity is diminished with fat saturation techniques. Pathology of lipomas shows mature adipose tissue, without evidence of malignancy or dedifferentiation.3 Cells appear large, regular, polygonal, reticulated, and optically empty with delicate cytoplasmic membranes and unremarkable, eccentric nuclei consistent with mature fat.2 Macroscopically, they are soft, yellow, fusiform tumours, with indistinct intraparenchymal margins.2
Isolated spinal cord lipoma
Fig. 1 T1-weighted sagittal image showing well defined ovoid intradural lesion at T2/3 level. The high signal intensity is consistent with fat.
Fig. 2 T2-weighted sagittal image of the lesion also shows high signal intensity.
ª 2003 Elsevier Ltd. All rights reserved.
693
Fig. 3 STIR (fat saturation) sagittal image showing reduced signal intensity from the lesion. This sequence demonstrates the tissue to be composed of fat.
Fig. 4
T1-weighted axial image at level of T2 vertebra.
Fig. 5
T2-weighted axial image at level of T2 vertebra.
Journal of Clinical Neuroscience (2003) 10(6)
694 Umegaki et al.
The overwhelming neurosurgical opinion regarding treatment of spinal cord lipoma is that surgical debulking of the tumour is the goal, and not excision. Indeed, total excision has generally shown less post-operative improvement, and in some cases significant worsening of symptoms. Lipomas are felt to be congenital tumours and intimately adherent to the normal neural tissue of the spinal cord.3 Intraoperative ultrasound may prove to be useful, as lipomas are echogenic lesions, thus the cranial and caudal poles can be determined. CO2 laser is the preferred instrument of choice for debulking, which vapourises the tumour due to the high water content of the lipoma.3 Unfortunately surgical outcomes are generally poor. Although localised back pain is often reduced, neurological function is largely unchanged, and in some patients is worse. This may be due to the congenital nature of the lipoma replacing neural tissue during embryonic development, so fewer redundant spinal tracts form, and thus there is less physiological reserve of the spinal cord.
REFERENCES 1. Gower D, Engles C, Friedman E. Thoracic intraspinal lipoma. Br J Neurosurg 1994; 8(6): 761–764. 2. Liebeskind et al. Intraspinal lipomas. Neuroradiology 1974; 7(4): 198–200. 3. Lee et al. Intramedullary spinal cord lipomas. J Neurosurg 1995; 82: 394–400. 4. Ammerman et al. Intradural lipomas of the spinal cord. J Neurosurg 1976; 44(3): 331–336. 5. Kogler A, Orsolic K, Kogler V. Intramedullary lipoma of dorsocervicothoracic spinal cord with intracranial extension and hydrocephalus. Pediatr Neurosurg 1998; 28: 257–260.
ª 2003 Elsevier Ltd. All rights reserved. Journal of Clinical Neuroscience (2003) 10(6), 694–696 0967-5868/$ - see front matter ª 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2002.11.001
Keywords: bispectral index, suppression ratio, hemorrhagic shock, cerebral ischemia, cerebral perfusion pressure Received 5 September 2000 Accepted 10 November 2002 Correspondence to: K. Hirota MD, Department of Anesthesiology, University of Hirosaki, School of Medicine, Hirosaki 036-8563, Japan. Tel.: +81-172-395113; Fax: +81-172-39-5112; E-mail: [email protected]
INTRODUCTION The bispectral index (BIS) monitor has been used in the clinic to enable control of sedation levels during general anaesthesia.1;2 In addition, several reports3;4 suggest that a reduction in BIS and 95% spectral edge frequency (SEF) or an increase in the suppression ratio (SR) may result not only from an increase in depth of hypnosis but also from a decrease in cerebral blood flow and oxygen supply. Thus the BIS monitor may be useful for monitoring cerebral ischemia, which is particularly important during general anaesthesia. We report a marked decrease in BIS with SR elevation during general anaesthesia, which may be due to a severe reduction in cerebral perfusion pressure secondary to a large cervical haematoma. CASE REPORT
A marked decrease in bispectral index with elevation of suppression ratio by cervical haematoma reducing cerebral perfusion pressure N. Umegaki MD, K. Hirota MD, M. Kitayama Y. Yatsu MD, H. Ishihara MD, A. Mtasuki MD
MD,
Department of Anesthesiology, University of Hirosaki, School of Medicine, Hirosaki 036-8563, Japan
Summary A 77-year-old man with a ruptured abdominal aortic aneurysm undergoing aneurysmectomy were anaesthetised with ketamine under bispectral index (BIS) monitoring, which is a clinical EEG monitor for measurement of depth of anaesthesia/ sedation. First marked BIS reduction with elevation of suppression ratio (SR) was observed following severe hypotension by deflation of the aortic occlusion balloon. The re-inflation and rapid blood transfusion improved haemodyanamics and BIS and SR. At second marked BIS reduction with SR elevation, a heavy cervical swelling due to a massive subcutaneous haematoma around the previously mis-punctured right carotid artery extending throughout the whole neck was observed without hypotension. Cervical relief incision improved the BIS and SR. The present case suggests that BIS monitor may be a simple and convenient monitor for cerebral ischaemia detection. Journal of Clinical Neuroscience (2003) 10(6)
A 77-year-old man (163 cm, 59 kg) presenting with haemorrhagic shock secondary to rupture of an abdominal aortic aneurysm was admitted to our emergency room from an affiliated hospital. In the affiliated hospital, the patient’s trachea was intubated and he was resuscitated with blood transfusion, fluid loading and a dopamine infusion via right femoral and cephalic venous lines. On arrival at this unit the right anterior cervix was slightly swollen as the right carotid artery had been mispunctured when placing a central venous line into right internal jugular vein. Blood pressure was around 40/20 mmHg despite a dopamine infusion of 10 lg/kg/ min. The patient was drowsy although the pupils showed isocoria without dilatation. Thus, adrenaline infusion started at 0.1 lg/kg/ min, and a radiologist was asked to insert an occlusion balloon into the abdominal aorta via the left brachial artery to maintain blood pressure. As the blood pressure increased to 90/40 mmHg, the patient was moved to the operating theatre to undergo aneurysmectomy with Y-graft replacement as an emergency. On arrival in operating theatre, a BIS monitor (model A-1050, Aspect Medical Systems) was applied, and BIS and SR were continuously recorded. The BIS and SR were 55 and 0, respectively, before the induction of anaesthesia despite the absence of analgesics and sedatives. Anaesthesia was induced with ketamine 50 mg and maintained with continuous intravenous infusion of ketamine at 1 mg/kg/h. Muscle relaxation was achieved and maintained with intermittent vecuronium administration. Although nasal temperature probe indicated a temperature of 31.9 C, we did not warm the patient as this hypothermia may be beneficial for brain protection. Arterial blood gas and blood cell counts before the induction of anaesthesia showed severe anaemia (Hb 2.0 g/dl) and metabolic acidosis (pH 6.95, base excess )24.8 mEq/l) hence a massive blood transfusion was given and the acidosis was corrected with 7% NaHCO3 . Following the commencement of surgery, the occlusion balloon was deflated a single time. ª 2003 Elsevier Ltd. All rights reserved.
Isolated spinal cord lipoma R. Pathi1 MBBS (HONS) ADEL, M. Kiley2 MBBS FRACP, M. Sage3 MD FRANZCR FRCR FRCP(ED) FRCP(LON) FHKCR(HON) 1 Department of Medical Imaging, Flinders Medical Centre, Bedford Park, SA, Australia, 2Department of Neurology, Royal Adelaide Hospital, SA, Australia, 3 Department of Medical Imaging, Flinders Medical Centre, Bedford Park, SA, Australia
Summary A case of isolated intradural spinal cord lipoma is presented. Most isolated spinal cord lipomas are intradural extramedullary, and the most common location is subpial. True intramedullary lipomas are very rare. Patient history is usually of months to years of local back pain, with recent escalation of pain and development of neurological symptoms. MRI examination shows a well circumscribed lesion of high signal on both T1 and T2 weighted images, and suppression on fat saturation sequence. Subtotal resection is the surgical aim. This improves pain but neurological symptoms rarely improve, usually are unchanged, and occasionally are worse. ª 2003 Elsevier Ltd. All rights reserved. Journal of Clinical Neuroscience (2003) 10(6), 692–694 0967-5868/$ - see front matter ª 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2003.01.001
Keywords: spinal cord lipoma, intradural Received 28 December 2002 Accepted 18 January 2003 Correspondence to: Dr. Ramon Pathi, Department of Radiology, Queen Elizabeth Hospital, Woodville, SA 5011, Australia. Tel.: +61-8-82045855; Fax: +61-8-82043091.
INTRODUCTION Although lipomas of the spinal cord associated with spinal dysraphism are not infrequent, isolated spinal cord lipomas in the absence of such congenital abnormalities are rare. CASE REPORT A 28-year-old man presented for assessment of back pain and weakness of the left leg. At the age of 18 he developed persistent mid-thoracic back pain, which was only partially alleviated by physiotherapy. Over the 12 months prior to presentation his pain progressively worsened. In addition, he had noted that over recent years his left leg appeared smaller than his right leg and his left knee had a tendency to spontaneously give way. He complained of “impaired sensation” over the left foot, stating that when riding his motorbike he had to look down at his foot to ensure that it was on the pedal. On closer questioning he also described a non-specific alteration of sensation of the right leg. Bladder and bowel function was normal and there were no symptoms referable to the upper limbs. Neurological examination revealed normal cranial nerves and upper limbs. On inspection his left leg was smaller than the right, but without evidence of muscle wasting. There was hypertonia with sustained clonus, hyperreflexia and pyramidal weakness on the left. Joint position was markedly impaired on 692
the left with errors at both the toes and ankles, and spinothalamic sensation was reduced over the right leg and trunk up to the level of T6-7. The clinical presentation was consistent with a lesion of the left mid thoracic spinal cord, giving rise to a hemi-cord syndrome (Brown-Sequard Syndrome). The patient therefore went on to have an MRI of his thoracic spine which showed a well defined ovoid lesion at the T2/3 level of both high T1 and T2 signal intensity (Figs. 1, 2, 4 and 5), with suppression on the fat saturation sequence (Fig. 3). There was mass effect and displacement of the cord. The spinal canal was mildly dilated at this level, without extension through neural foramen. He subsequently underwent incomplete surgical resection of the lesion and post-operatively noted subjective improvement, though there was little objective change noted in the immediate post-operative period. Pathological examination of the lesion confirmed a lipomatous tumour. DISCUSSION The first ever report of an intradural lipoma was by Gowers in 1897.1 Lipomas of the spinal cord are most frequent in association with spina bifida (lipomyelomeningocoele). These are more commonly located in the lumbosacral or cervical region, and it is thought this relates to the last sites of closure of the embryonic neural arch, with abnormal inclusion of adipose tissue within the closing lips of the neural groove.2 On the other hand, spinal cord lipomas not associated with spinal dysraphism are rare and make up less than 1% of all spinal cord tumours. There are many reports of extradural lipomas, or intradural extramedullary lipomas, but true intramedullary lipomas are exceedingly infrequent. The common intradural location is subpial.5 Spinal cord lipomas seem to have a peak presentation between 10 and 40 years, with a slight male preponderance. The usual presentation is of a long indolent history, followed by a dramatic worsening over months. All patients describe local back pain in the region of the lipoma, without radicular pain. Paraparesis, sensory disturbance, gait difficulties, incoordination, urinary incontinence, and impotence have all been described.3;4 One or more of these is always present and may prompt the patient to seek medical attention. It is postulated that slow growth of the lipoma allows accommodation within the spinal canal without compromise of function, until a point is reached where further growth causes a rapid decline in function.3 Plain radiographs can frequently be normal, but sometimes may show widening of the spinal canal, scalloping of the vertebral bodies, or destruction of the pedicle.4 These findings can indicate a mass lesion, but are not specific for lipoma. Myelography is now rarely performed but will show a complete or partial block in the flow of contrast within the subarachnoid space.2 Computed tomography can demonstrate a low-density lesion within the spinal cord, but MRI is diagnostic for lipoma.3 Lesions show high signal on T1-weighted images, and decreased signal intensity on T2-weighted images. The lipoma is well defined from surrounding cord tissue, and usually ovoid in the longitudinal axis of the cord. There is no enhancement on administration of gadolinium, while signal intensity is diminished with fat saturation techniques. Pathology of lipomas shows mature adipose tissue, without evidence of malignancy or dedifferentiation.3 Cells appear large, regular, polygonal, reticulated, and optically empty with delicate cytoplasmic membranes and unremarkable, eccentric nuclei consistent with mature fat.2 Macroscopically, they are soft, yellow, fusiform tumours, with indistinct intraparenchymal margins.2
Isolated spinal cord lipoma
Fig. 1 T1-weighted sagittal image showing well defined ovoid intradural lesion at T2/3 level. The high signal intensity is consistent with fat.
Fig. 2 T2-weighted sagittal image of the lesion also shows high signal intensity.
ª 2003 Elsevier Ltd. All rights reserved.
693
Fig. 3 STIR (fat saturation) sagittal image showing reduced signal intensity from the lesion. This sequence demonstrates the tissue to be composed of fat.
Fig. 4
T1-weighted axial image at level of T2 vertebra.
Fig. 5
T2-weighted axial image at level of T2 vertebra.
Journal of Clinical Neuroscience (2003) 10(6)
694 Umegaki et al.
The overwhelming neurosurgical opinion regarding treatment of spinal cord lipoma is that surgical debulking of the tumour is the goal, and not excision. Indeed, total excision has generally shown less post-operative improvement, and in some cases significant worsening of symptoms. Lipomas are felt to be congenital tumours and intimately adherent to the normal neural tissue of the spinal cord.3 Intraoperative ultrasound may prove to be useful, as lipomas are echogenic lesions, thus the cranial and caudal poles can be determined. CO2 laser is the preferred instrument of choice for debulking, which vapourises the tumour due to the high water content of the lipoma.3 Unfortunately surgical outcomes are generally poor. Although localised back pain is often reduced, neurological function is largely unchanged, and in some patients is worse. This may be due to the congenital nature of the lipoma replacing neural tissue during embryonic development, so fewer redundant spinal tracts form, and thus there is less physiological reserve of the spinal cord.
REFERENCES 1. Gower D, Engles C, Friedman E. Thoracic intraspinal lipoma. Br J Neurosurg 1994; 8(6): 761–764. 2. Liebeskind et al. Intraspinal lipomas. Neuroradiology 1974; 7(4): 198–200. 3. Lee et al. Intramedullary spinal cord lipomas. J Neurosurg 1995; 82: 394–400. 4. Ammerman et al. Intradural lipomas of the spinal cord. J Neurosurg 1976; 44(3): 331–336. 5. Kogler A, Orsolic K, Kogler V. Intramedullary lipoma of dorsocervicothoracic spinal cord with intracranial extension and hydrocephalus. Pediatr Neurosurg 1998; 28: 257–260.
ª 2003 Elsevier Ltd. All rights reserved. Journal of Clinical Neuroscience (2003) 10(6), 694–696 0967-5868/$ - see front matter ª 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2002.11.001
Keywords: bispectral index, suppression ratio, hemorrhagic shock, cerebral ischemia, cerebral perfusion pressure Received 5 September 2000 Accepted 10 November 2002 Correspondence to: K. Hirota MD, Department of Anesthesiology, University of Hirosaki, School of Medicine, Hirosaki 036-8563, Japan. Tel.: +81-172-395113; Fax: +81-172-39-5112; E-mail: [email protected]
INTRODUCTION The bispectral index (BIS) monitor has been used in the clinic to enable control of sedation levels during general anaesthesia.1;2 In addition, several reports3;4 suggest that a reduction in BIS and 95% spectral edge frequency (SEF) or an increase in the suppression ratio (SR) may result not only from an increase in depth of hypnosis but also from a decrease in cerebral blood flow and oxygen supply. Thus the BIS monitor may be useful for monitoring cerebral ischemia, which is particularly important during general anaesthesia. We report a marked decrease in BIS with SR elevation during general anaesthesia, which may be due to a severe reduction in cerebral perfusion pressure secondary to a large cervical haematoma. CASE REPORT
A marked decrease in bispectral index with elevation of suppression ratio by cervical haematoma reducing cerebral perfusion pressure N. Umegaki MD, K. Hirota MD, M. Kitayama Y. Yatsu MD, H. Ishihara MD, A. Mtasuki MD
MD,
Department of Anesthesiology, University of Hirosaki, School of Medicine, Hirosaki 036-8563, Japan
Summary A 77-year-old man with a ruptured abdominal aortic aneurysm undergoing aneurysmectomy were anaesthetised with ketamine under bispectral index (BIS) monitoring, which is a clinical EEG monitor for measurement of depth of anaesthesia/ sedation. First marked BIS reduction with elevation of suppression ratio (SR) was observed following severe hypotension by deflation of the aortic occlusion balloon. The re-inflation and rapid blood transfusion improved haemodyanamics and BIS and SR. At second marked BIS reduction with SR elevation, a heavy cervical swelling due to a massive subcutaneous haematoma around the previously mis-punctured right carotid artery extending throughout the whole neck was observed without hypotension. Cervical relief incision improved the BIS and SR. The present case suggests that BIS monitor may be a simple and convenient monitor for cerebral ischaemia detection. Journal of Clinical Neuroscience (2003) 10(6)
A 77-year-old man (163 cm, 59 kg) presenting with haemorrhagic shock secondary to rupture of an abdominal aortic aneurysm was admitted to our emergency room from an affiliated hospital. In the affiliated hospital, the patient’s trachea was intubated and he was resuscitated with blood transfusion, fluid loading and a dopamine infusion via right femoral and cephalic venous lines. On arrival at this unit the right anterior cervix was slightly swollen as the right carotid artery had been mispunctured when placing a central venous line into right internal jugular vein. Blood pressure was around 40/20 mmHg despite a dopamine infusion of 10 lg/kg/ min. The patient was drowsy although the pupils showed isocoria without dilatation. Thus, adrenaline infusion started at 0.1 lg/kg/ min, and a radiologist was asked to insert an occlusion balloon into the abdominal aorta via the left brachial artery to maintain blood pressure. As the blood pressure increased to 90/40 mmHg, the patient was moved to the operating theatre to undergo aneurysmectomy with Y-graft replacement as an emergency. On arrival in operating theatre, a BIS monitor (model A-1050, Aspect Medical Systems) was applied, and BIS and SR were continuously recorded. The BIS and SR were 55 and 0, respectively, before the induction of anaesthesia despite the absence of analgesics and sedatives. Anaesthesia was induced with ketamine 50 mg and maintained with continuous intravenous infusion of ketamine at 1 mg/kg/h. Muscle relaxation was achieved and maintained with intermittent vecuronium administration. Although nasal temperature probe indicated a temperature of 31.9 C, we did not warm the patient as this hypothermia may be beneficial for brain protection. Arterial blood gas and blood cell counts before the induction of anaesthesia showed severe anaemia (Hb 2.0 g/dl) and metabolic acidosis (pH 6.95, base excess )24.8 mEq/l) hence a massive blood transfusion was given and the acidosis was corrected with 7% NaHCO3 . Following the commencement of surgery, the occlusion balloon was deflated a single time. ª 2003 Elsevier Ltd. All rights reserved.