Surgical Intervention is Associated with Improvement in Health-Related Quality of Life Outcomes in Patients with Symptomatic Sacral Tarlov Cysts: Results from a Prospective Longitudinal Cohort Study

OBJECTIVE

The treatment of symptomatic Tarlov cysts remains a controversial topic within neurosurgery. We describe our experience with patients who underwent surgical intervention for sacral Tarlov cysts at a single institution. General and disease-specific outcome measures were used to assess health-related quality of life.

METHODS

Patients who underwent surgical treatment for one or more sacral Tarlov cysts between 2018 and 2021 were included. The Tarlov Cyst Quality of Life (TCQoL), a validated disease-specific measure, was the primary outcome of the study. Secondary outcomes included general outcome measures: 36-Item Short Form Survey, the Oswestry Disability Index, and Visual Analog Scale. Patients were followed at 3, 6, and 12 months postoperative. Repeated measures analyses were used to assess change from preoperative to 12 months postoperative.

RESULTS

Data were obtained from 144 patients who underwent surgery for sacral Tarlov cysts, average age 52.3 ± 11.3 years, 90.3% female. Patients reported significant mean improvement on the TCQoL over time (preoperative 3.2±0.1; 3-months postoperative 2.1±0.1; 6-months 1.9±0.1; 12-months 1.9±0.1; P< 0.001). Patient age and duration of symptoms were not associated with outcome. 82.3% of patients reported improvement on TCQoL. There was not a significant difference in the proportion of patients reporting improvement on TCQoL by cyst size (small 90.9% vs. large 77.9%; P = 0.066).

CONCLUSION

Our longitudinal series demonstrated patient-reported improvement following surgery for symptomatic sacral Tarlov cysts using a validated disease-specific health-related quality of life scale through 12 months following surgery. Patient age and preoperative duration of symptoms were not correlated with outcome.

Sacral Tarlov perineurial cysts: a systematic review of treatment options

Tarlov perineurial spinal cysts (TCs) are an underrecognized cause of spinal neuropathic symptoms. TCs form within the sensory nerve root sleeves, where CSF extends distally and can accumulate pathologically. Typically, they develop at the sacral dermatomes where the nerve roots are under the highest hydrostatic pressure and lack enclosing vertebral foramina. In total, 90% of patients are women, and genetic disorders that weaken connective tissues, e.g., Ehlers-Danlos syndrome, convey considerable risk. Most small TCs are asymptomatic and do not require treatment, but even incidental visualizations should be documented in case symptoms develop later. Symptomatic TCs most commonly cause sacropelvic dermatomal neuropathic pain, as well as bladder, bowel, and sexual dysfunction. Large cysts routinely cause muscle atrophy and weakness by compressing the ventral motor roots, and multiple cysts or multiroot compression by one large cyst can cause even greater cauda equina syndromes. Rarely, giant cysts erode the sacrum or extend as intrapelvic masses. Disabling TCs require consideration for surgical intervention. The authors' systematic review of treatment analyzed 31 case series of interventional percutaneous procedures and open surgical procedures. The surgical series were smaller and reported somewhat better outcomes with longer term follow-up but slightly higher risks. When data were lacking, authorial expertise and case reports informed details of the specific interventional and surgical techniques, as well as medical, physical, and psychological management. Cyst-wrapping surgery appeared to offer the best long-term outcomes by permanently reducing cyst size and reconstructing the nerve root sleeves. This curtails ongoing injury to the axons and neuronal death, and may also promote axonal regeneration to improve somatic and autonomic sacral nerve function.

Surgical Intervention is Associated with Improved Outcomes in Patients with Symptomatic Cervical Spine Tarlov Cysts: Results from a Prospective Cohort Study

BACKGROUND

Tarlov cysts are known contributors to radiculopathy but are often misdiagnosed and mismanaged due to a paucity of information. This is particularly true of cervical spine Tarlov cysts because most attention has been focused on sacral cysts. In this study, we describe our longitudinal experience with patients who underwent surgery for cervical spine Tarlov cysts. We hypothesized that patients undergoing surgical treatment for cervical spine Tarlov cysts would report improvement following surgery.

METHODS

We conducted a prospective study of patients who underwent surgical treatment for cervical Tarlov cysts between 2010 and 2021. The Short-Form 36-item survey (SF-36) was administered at the preoperative and follow-up visits. Repeated measures analyses were used to assess changes from preoperatively to postoperatively.

RESULTS

A total of 37 patients with cervical spine cysts were included in the study. Follow-up data were available for 27 patients with a median follow-up of 1 year. Of the cohort, 97.3% were women, with an average age of 47.5 ± 10.3 years. Patients reported statistically significant improvement in 2 of the 4 SF-36 physical health domains (physical function, P< 0.001; and bodily pain, P < 0.001) and 2 of the 4 mental health domains (vitality/energy, P < 0.003; and social functioning, P = 0.007). Patients also reported less interference in work, education, and retirement activities at follow-up (P = 0.017).

CONCLUSIONS

Our longitudinal series consisted of patients with symptomatic cervical spine Tarlov cysts, which, to the best of our knowledge, is the largest series described. Significant improvements in the SF-36 domains were documented, indicating these patients can be successfully treated surgically.

Giant sacral meningeal diverticulum containing a thickened filum with lipoma in an adult with spinal cord tethering. Case report and review of the literature

An unusual case of a patient with a giant intrasacral meningeal diverticulum and spinal cord tethering with a thickened filum is presented. Instead of being empty as is typical, the meningeal diverticulum in this case contained a segment of the thickened tethering filum, which entered from the thecal sac through an ostium. A search of the literature revealed no prior description of a meningeal diverticulum containing a portion of tethered filum or any other structure. Only 2 previous cases of intrasacral meningeal cyst and spinal cord tethering with a thickened filum were found, both in the non-English literature.

Giant sacral meningeal diverticula: surgical implications of the “thecal tip” sign

✓ The surgical anatomy of giant sacral meningeal diverticula varies greatly depending on whether they develop ventral or dorsal to the thecal sac and spinal nerve roots. The ability to distinguish between the two lesion types preoperatively is therefore advantageous. The authors present a method of distinguishing ventral from dorsal meningeal diverticula on magnetic resonance imaging using the “thecal tip sign.” They also describe the differences in operative technique required for resection of each type of diverticular cyst.

Viral shedding and biodistribution of G207, a multimutated, conditionally replicating herpes simplex virus type 1, after intracerebral inoculation in aotus

G207 is a multimutated, conditionally replicating herpes simplex virus type 1 (HSV-1) that is currently in clinical trial for patients with malignant glioma. G207 exhibits an efficient oncolytic activity in tumor cells, yet minimal toxicity in normal tissue when injected into the brains of HSV-susceptible mice or nonhuman primates. In this study, we evaluated the shedding and biodistribution of clinical-grade G207 after intracerebral inoculation (3 x 10(7) pfu) in four New World owl monkeys (Aotus nancymae). Using PCR analyses and viral cultures, neither infectious virus nor viral DNA was detected from tear, saliva, or vaginal secretion samples at any time point up to 1 month postinoculation. Analyses of tissues obtained at necropsy at 1 month from two of the four monkeys, plus one monkey inoculated with laboratory-grade G207 (10(9) pfu) 2 years earlier, showed the distribution of G207 DNA restricted to the brain, although infectious virus was not isolated. Histopathology revealed normal brain tissues including the sites of inoculation. A measurable increase of serum anti-HSV antibody titer was observed in all monkeys, as early as 21 days postinoculation. The results ascertain the safety of G207 in the brain and indicate that strict biohazard management may not be required for G207-treated patients.

Intraoperative computed tomography for complex craniocervical operations and spinal tumor resections

OBJECTIVE

To improve intraoperative observation of unexposed anatomic features and to verify surgical correction, a mobile computed tomographic (CT) scanner has been introduced into the operating room. To date, intraoperative CT scanning has been used predominantly for intracranial procedures. We report on the expanded use of intraoperative CT scanning for spinal surgery, because CT scanning provides excellent observation of osseous pathological features. We report on our first 17 cases, which involved complex craniocervical operations and spinal tumor resections.

METHODS

The Tomoscan M CT scanner (Philips Medical Systems, Eindhoven, The Netherlands) is mobile and consists of a translatable gantry, a translatable table, and an operator's workstation. In the operating room, the patient is placed on the CT table and prepared in the usual manner. The aperture of the gantry is covered with sterile plastic drapes. The gantry is docked to the table for intraoperative CT scanning as needed for navigation and verification during surgery. Each series of scans requires approximately 15 to 20 minutes.

RESULTS

Our initial experience with neurosurgical spinal cases demonstrated that the use of intraoperative CT scanning changed the course of surgery in 6 of 17 cases. CT scanning was beneficial in facilitating adequate ventral clival and craniocervical decompressions, promoting more complete tumor resections, and verifying correct graft and instrument placement before surgical closing. Other settings in which we have found the mobile CT scanner useful include the neurointerventional suite and the intensive care unit; it is also useful for radiotherapy planning.

CONCLUSION

On the basis of findings for our first 17 spinal surgery cases, we conclude that intraoperative CT scanning of the spine is both feasible and beneficial for select complex spinal procedures from the craniocervical junction to the sacrum.

Conditionally replicating herpes simplex virus mutant, G207 for the treatment of malignant glioma: results of a phase I trial

G207 is a conditionally replicating derivative of herpes simplex virus (HSV) type-1 strain F engineered with deletions of both gamma(1)34.5 loci and a lacZ insertion disabling the UL39 gene. We have demonstrated the efficacy of G207 in treating malignant glial tumors in athymic mice, as well as the safety of intracerebral G207 inoculation in mice and in Aotus nancymai. We sought to determine the safety of G207 inoculation into cerebral malignant glial tumors in humans. Criteria for inclusion into this dose-escalation study were the diagnosis of histologically proven malignant glioma, Karnofsky score > or = 70, recurrence despite surgery and radiation therapy, and an enhancing lesion greater than 1 cm in diameter. Serial magnetic resonance images were obtained for volumetric analysis. The trial commenced at a dose of 10(6) plaque forming units (p.f.u.) inoculated at a single enhancing site and was completed when the 21st patient was inoculated with 3x10(9) p.f.u. at five sites. While adverse events were noted in some patients, no toxicity or serious adverse events could unequivocally be ascribed to G207. No patient developed HSV encephalitis. We found radiographic and neuropathologic evidence suggestive of anti-tumor activity and long-term presence of viral DNA in some cases.

Attenuated, replication-competent herpes simplex virus type 1 mutant G207: safety evaluation of intracerebral injection in nonhuman primates

This study examined the safety of intracerebral inoculation of G207, an attenuated, replication-competent herpes simplex virus type 1 (HSV-1) recombinant, in nonhuman primates. Sixteen New World owl monkeys (Aotus nancymae [karyotype 1, formerly believed to be A. trivirgatus]), known for their exquisite susceptibility to HSV-1 infection, were evaluated. Thirteen underwent intracerebral inoculation with G207 at doses of 10(7) or 10(9) PFU, two were vehicle inoculated, and one served as an infected wild-type control and received 10(3) PFU of HSV-1 strain F. HSV-1 strain F caused rapid mortality and symptoms consistent with HSV encephalitis, including fever, hemiparesis, meningitis, and hemorrhage in the basal ganglia. One year after G207 inoculation, seven of the animals were alive and exhibited no evidence of clinical complications. Three deaths resulted from nonneurologic causes unrelated to HSV infection, and three animals were sacrificed for histopathologic examination. Two animals were reinoculated with G207 (10(7) PFU) at the same stereotactic coordinates 1 year after the initial G207 inoculation. These animals were alive and healthy 2 years after the second inoculation. Cerebral magnetic resonance imaging studies performed both before and after G207 inoculation failed to reveal radiographic evidence of HSV-related sequelae. Despite the lack of outwardly observable HSV pathology, measurable increases in serum anti-HSV titers were detected. Histopathological examination of multiple organ tissues found no evidence of HSV-induced histopathology or dissemination. We conclude that intracerebral inoculation of up to 10(9) PFU of G207, well above the efficacious dose in mouse tumor studies, is safe and therefore appropriate for human clinical trials.

Hepatoma-specific antitumor activity of an albumin enhancer/promoter regulated herpes simplex virus in vivo

Targeting viral vectors to appropriate cell types so that normal cells are not adversely affected is an important goal for gene therapy. Previously, we described a novel approach to viral gene therapy using a conditional, replication-competent herpes simplex virus (HSV), where replication and associated cytotoxicity are limited to a specific cell-type by the regulated expression of an essential immediate-early viral gene product. In this report we analyze the hepatoma-specific replication, cytotoxicity and anti-tumor effect of recombinant HSV G92A, regulated by the albumin enhancer/promoter. G92A efficiently replicated in vitro in two human hepatoma cell lines expressing albumin, but not in four human non-hepatoma, albumin-non-expressing tumor cell lines, while all cell lines were equally susceptible to a tissue nonspecific HSV recombinant, hrR3. In vivo, G92A replicated well in subcutaneous xenografts of human hepatoma cells (Hep3B) in athymic mice, but not in non-hepatoma subcutaneous tumors (PC3 and HeLa), whereas, hrR3 replicated well in both tumor types. Intratumoral inoculation of G92A inhibited the growth of established subcutaneous hepatoma tumors in nude mice, but not prostate tumors. Replication-competent viral vectors controlled by cell-specific transcriptional regulatory sequences provide a new therapeutic strategy for tumor therapy.

Spondyloptotic fracture of the cervical spine in a pregnant, anemic Jehovah's Witness: technical and ethical considerations. Case report

The authors present the case of a 15-year-old Jehovah's Witness with a hematocrit level of 19% who was 4 months pregnant and had a two-level spondyloptotic cervical spine fracture. The patient was transferred to Georgetown University Medical Center with C-5 quadriplegia 3 weeks after having been injured in an automobile collision. The neurosurgical issues in this case included addressing a rare cervical spine injury, assessing and treating a vertebral artery injury, and performing surgery on a pregnant minor with severe anemia who held strong Jehovah's Witness beliefs. An ethics consultation was convened to determine the validity of a pregnant minor's refusal to undergo transfusion on the grounds of her religious beliefs. This case illustrates the potential benefits of thorough technical and ethical evaluations and reveals how they may contribute to the delivery of care in complex neurosurgical cases. To the authors' knowledge, this is the first two-level spondyloptotic cervical spine fracture dislocation to be reported in the literature. The added complexities of the case, given that the patient was an anemic, adolescent, pregnant Jehovah's Witness who refused blood transfusion, also appear to be unprecedented.

Human T-lymphotropic virus type II in Panamanian Guaymi Indians

BACKGROUND

Currently, human T-lymphotropic virus type II (HTLV-II) is the most prevalent human retrovirus, detected in persons presenting to donate blood in the United States. Only scant information is available with which to counsel HTLV-II-seropositive deferred donors or other persons about the ways in which they may spread HTLV-II to others.

STUDY DESIGN AND METHODS

To increase understanding of the modes of transmission of HTLV-II, a seroepidemiologic study was conducted among Panamanian Guaymi Indians, a recently identified focus of endemic HTLV-II infection. Subjects were tested for serologic evidence of infection by HTLV-II, HTLV type I, hepatitis B virus, and nine other infectious agents by enzyme immunoassays and specific confirmatory tests.

RESULTS

Nine (8.3%) of 109 persons tested HTLV-II-seropositive. HTLV-II seropositivity was more likely in persons with serologic evidence of prior hepatitis B virus infection. Sexual contact with HTLV-II-seropositive partners, but neither parenteral exposure nor breast-feeding, was identified as a risk factor for HTLV-II.

CONCLUSION

In Guaymi Indians, HTLV-II appears to be spread primarily through sexual transmission.

Mutational analysis of a predicted zinc-binding motif in the 26-kilodalton protein encoded by the vaccinia virus A2L gene: correlation of zinc binding with late transcriptional transactivation activity

Transient transfection assays indicated that A2L is one of three vaccinia virus intermediate genes that are required for the transcriptional transactivation of viral late genes. We have expressed the A2L open reading frame in Escherichia coli and shown by blotting experiments that the 26-kDa protein binds zinc, a property predicted by the presence of a CX2CX13CX2C zinc finger motif. The specificity for zinc binding was demonstrated by competition with other metals. The role of the sequence motif in zinc binding was established by analysis of a series of mutations, including truncations and conservative single amino acid substitutions. Mutations that reduced zinc binding in vitro prevented the ability of A2L to transactivate late genes in vivo.