Effects of short term sacral nerve stimulation on anal and rectal function in patients with anal incontinence.
BACKGROUND: Some patients with faecal incontinence are not amenable to simple surgical sphincter repair, due to sphincter weakness in the absence of a structural defect. AIMS: To evaluate the efficacy and possible mode of action of short term stimulation of sacral nerves in patients with faecal incontinence and a structurally intact external anal sphincter. PATIENTS: Twelve patients with faecal incontinence for solid or liquid stool at least once per week. METHODS: A stimulating electrode was placed (percutaneously in 10 patients, operatively in two) into the S3 or S4 foramen. The electrode was left in situ for a minimum of one week with chronic stimulation. RESULTS: Evaluable results were obtained in nine patients, with early electrode displacement in the other three. Incontinence ceased in seven of nine patients and improved notably in one; one patient with previous imperforate anus and sacral agenesis had no symptomatic response. Stimulation seemed to enhance maximum squeeze pressure but did not alter resting pressure. The rectum became less sensitive to distension with no change in rectal compliance. Ambulatory studies showed a possible reduction in rectal contractile activity and diminished episodes of spontaneous anal relaxation. CONCLUSIONS: Short term sacral nerve stimulation notably decreases episodes of faecal incontinence. The effect may be mediated via facilitation of striated sphincter muscle function, and via neuromodulation of sacral reflexes which regulate rectal sensitivity and contractility, and anal motility. (+info)
We report a case of myxopapillary ependymoma presenting as a primary tumor of the subcutaneous tissue in the sacrococcygeal region. The mass was large, well-encapsulated, lobulated, and multiseptated, with varying signal intensity on T1- and T2-weighted MR images caused by hemorrhagic necrosis, blood degradation products, and calcification. Only a small viable portion enhanced after administration of contrast material. Multiple lobules formed from fibrous septa and dystrophic calcification also characterize this tumor. (+info)
Chemical activation of cervical cell bodies: effects on responses to colorectal distension in lumbosacral spinal cord of rats.
We have shown that stimulation of cardiopulmonary sympathetic afferent fibers activates relays in upper cervical segments to suppress activity of lumbosacral spinal cells. The purpose of this study was to determine if chemical excitation (glutamate) of upper cervical cell bodies changes the spontaneous activity and evoked responses of lumbosacral spinal cells to colorectal distension (CRD). Extracellular potentials were recorded in pentobarbital-anesthetized male rats. CRD (80 mmHg) was produced by inflating a balloon inserted in the descending colon and rectum. A total of 135 cells in the lumbosacral segments (L(6)-S(2)) were activated by CRD. Seventy-five percent (95/126) of tested cells received convergent somatic input from the scrotum, perianal region, hindlimb, and tail; 99/135 (73%) cells were excited or excited/inhibited by CRD; and 36 (27%) cells were inhibited or inhibited/excited by CRD. A glutamate (1 M) pledget placed on the surface of C(1)-C(2) segments decreased spontaneous activity and excitatory CRD responses of 33/56 cells and increased spontaneous activity of 13/19 cells inhibited by CRD. Glutamate applied to C(6)-C(7) segments decreased activity of 10/18 cells excited by CRD, and 9 of these also were inhibited by glutamate at C(1)-C(2) segments. Glutamate at C(6)-C(7) increased activity of 4/6 cells inhibited by CRD and excited by glutamate at C(1)-C(2) segments. After transection at rostral C(1) segment, glutamate at C(1)-C(2) still reduced excitatory responses of 7/10 cells. Further, inhibitory effects of C(6)-C(7) glutamate on excitatory responses to CRD still occurred after rostral C(1) transection but were abolished after a rostral C(6) transection in 4/4 cells. These data showed that C(1)-C(2) cells activated with glutamate primarily produced inhibition of evoked responses to visceral stimulation of lumbosacral spinal cells. Inhibition resulting from activation of cells in C(6)-C(7) segments required connections in the upper cervical segments. These results provide evidence that upper cervical cells integrate information that modulates activity of distant spinal neurons responding to visceral input. (+info)
Non-linear membrane properties of sacral sphincter motoneurones in the decerebrate cat.
1. Responses to pudendal afferent stimulation and depolarizing intracellular current injection were examined in sacral sphincter motoneurones in decerebrate cats. 2. In 16 animals examined, 2-10 s trains of electrical stimulation of pudendal afferents evoked sustained sphincter motoneurone activity lasting from 5 to >50 s after stimulation. The sustained response was observed in: 11 animals in the absence of any drugs; two animals after the intravenous administration of 5-hydroxytryptophan (5-HTP; <= 20 mg kg-1); one animal in which methoxamine was perfused onto the ventral surface of the exposed spinal cord; and two animals following the administration of intravenous noradrenergic agonists. 3. Extracellular and intracellular recordings from sphincter motoneurones revealed that the persistent firing evoked by afferent stimulation could be terminated by motoneurone membrane hyperpolarization during micturition or by intracellular current injection. 4. Intracellular recordings revealed that 22/40 sphincter motoneurones examined displayed a non-linear, steep increase in the membrane potential in response to depolarizing ramp current injection. The mean voltage threshold for this non-linear membrane response was -43 +/- 3 mV. Five of the 22 cells displaying the non-linear membrane response were recorded prior to the administration of 5-HTP; 17 after the intravenous administration of 5-HTP (<= 20 mg kg-1). 5. It is concluded that sphincter motoneurones have a voltage-sensitive, non-linear membrane response to depolarization that could contribute to sustained sphincter motoneurone firing during continence. (+info)
Combined anomaly of intramedullary arteriovenous malformation and lipomyelomeningocele.
We report a rare situation in which a lipomyelomeningocele and an intramedullary arteriovenous malformation (AVM) occurred together at the T11-L1 level in a 44-year-old man. MR images showed a hypervascular lesion intradurally and a fatty component extradurally. Spinal angiography revealed this lesion to be an intramedullary AVM with multiple feeding arteries from the right T12 and left T10 intercostal artery and the left L1 lumbar artery, drained by tortuous, dilated, perimedullary veins. (+info)
Sacral chordoma--a case report.
Chordoma, a rare malignant tumour of early adulthood, rarely presents in children. We report such a case of rare malignant tumour which was diagnosed in the first decade of life. (+info)
Isolated cardiac metastasis from sacral chordoma.
A 64-year-old woman presented with right heart failure caused by a cardiac tumor centered in the free wall of the right ventricle, accompanied by pericardial effusion. A match between the biopsy specimen and tissue removed 4 years earlier resulted in the diagnosis of a cardiac metastasis from a chordoma. Immunohistochemical staining was also useful in establishing the diagnosis. To alleviate the right ventricular outflow obstruction, a palliative operation was planned, resecting the tumor and performing a right ventriculoplasty, which was cancelled due to the extent of infiltration of the tumor, and instead a right atrium to pulmonary artery shunt was attempted using a vascular prosthesis, only to fail due to an inability to maintain blood flow through the prosthesis. Presently there are no definitive treatment options available, and some palliative chemotherapy is being performed. Single cardiac metastases from a chordoma are extremely rare. (+info)
Infantile arachnoid cyst compressing the sacral nerve root associated with spina bifida and lipoma--case report.
A 2-year-old boy presented with a rare sacral arachnoid cyst manifesting as gait disturbance. Neuroimaging revealed an intradural cyst in the sacral nerve root sheath associated with spina bifida occulta and a lipoma at the same level. At surgery, the conus medullaris was situated at the L-1 level and not tethered. The highly pressurized arachnoid cyst had exposed the dural sheath of the left S-2 nerve root and compressed the adjacent nerves. An S-2 nerve root pierced through the cyst. There was no communication between the cyst and spinal arachnoid space. We thought the one-way valve mechanism had contributed to the cyst enlargement and the nerve compression. Radical resection of the cyst was not attempted. A cyst-subarachnoid shunt was placed to release the intracystic pressure. Postoperatively, his gait disturbance improved and no deterioration occurred during the 4-year follow up. Both tethered cord syndrome and sacral arachnoid cyst in the nerve root sheath should be considered in pediatric progressive gait disturbance. Cyst-subarachnoid shunt is an alternative method to cyst resection or fenestration to achieve neurological improvement. (+info)