The genesis of low pressure hydrocephalus.

BACKGROUND: Low pressure hydrocephalus (LPH) is an uncommon entity. Recognition of this treatable condition is important when clinicians are faced with the paradox of symptomatic hydrocephalus despite low intracranial pressures (ICP). Its etiology remains enigmatic. METHODS: We identified patients with LPH from the prospective, inpatient neuro-intensive care database over a 4-year period (2006-2010). RESULTS: Nine patients with LPH were identified over a 4-year period. The time from diagnosis of the initial neurosurgical condition to development of LPH varied from 7 days to 5 years. The sub-zero drainage method of Pang and Altschuler was successful in all cases. LPH was accompanied by transependymal edema in five patients despite low ICP. Four patients developed LPH during their initial admission for intracranial bleeding. As patients entered the LPH state, the ICP remained in a normal range yet daily CSF output from the external ventricular drain was reduced. When LPH patients were drained at sub-zero levels, daily CSF output exceeded baseline values for several days and then receded to baseline. Long-term management was achieved with low pressure shunt systems: six programmable shunts; one valveless ventriculoperitoneal shunt; two ventriculopleural shunts. Conditions most commonly associated with LPH are: subarachnoid hemorrhage, chronic hydrocephalus, brain tumors, and chronic CNS infections. CONCLUSIONS: Low pressure hydrocephalus is a challenging diagnosis. The genesis of LPH was associated with a drop in EVD output, symptomatic ventriculomegaly, and a remarkable absence of intracranial hypertension. When LPH was treated with the sub-zero method, a 'diuresis' of CSF ensued. These observations support a Darcy's flux of brain interstitial fluid due to altered brain poroelastance; in simpler terms, a boggy brain state.

H1N1 encephalitis with malignant edema and review of neurologic complications from influenza.

BACKGROUND: Influenza virus infection of the respiratory tract is associated with a range of neurologic complications. The emergence of 2009 pandemic influenza A (H1N1) virus has been linked to neurological complications, including encephalopathy and encephalitis. METHODS: Case report and literature review. RESULTS: We reviewed case management of a 20-year old Hispanic male who developed febrile upper respiratory tract signs and symptoms followed by a confusional state. He had rapid neurologic decline and his clinical course was complicated by refractory seizures and malignant brain edema. He was managed with oseltamavir and peramavir, corticosteroids, intravenous gamma globulin treatment, anticonvulsants, intracranial pressure management with external ventricular drain placement, hyperosmolar therapy, sedation, and mechanical ventilation. Reverse transcriptase polymerase chain reaction analysis of nasal secretions confirmed 2009 H1N1 virus infection; cerebrospinal fluid (CSF) was negative for 2009 H1N1 viral RNA. Follow-up imaging demonstrated improvement in brain edema but restricted diffusion in the basal ganglia. We provide a review of the clinical spectrum of neurologic complications of seasonal influenza and 2009 H1N1, and current approaches towards managing these complications. CONCLUSIONS: 2009 H1N1-associated acute encephalitis and encephalopathy appear to be variable in severity, including a subset of patients with a malignant clinical course complicated by high morbidity and mortality. Since the H1N1 influenza virus has not been detected in the CSF or brain tissue in patients with this diagnosis, the emerging view is that the host immune response plays a key role in pathogenesis.

A 10-Year Analysis of 3693 Craniotomies during a Transition to Multidisciplinary Teams, Protocols, and Pathways.

INTRODUCTION: A Cochrane review of teams, protocols, and pathways demonstrated improved care efficiency and outcomes over a traditional model. Little is known about this approach for craniotomy. METHODS: This observational study involved sequential implementation of a multidisciplinary team, protocols, and a craniotomy pathway. Data on 3693 admissions were retrospectively reviewed at a tertiary care neurosurgery center from 2008 to 2017 for the top 6 diagnosis-related group codes. In June 2016, a searchable discharge summary template in the electronic medical record was implemented to capture data regarding quality, efficiency, and outcomes. RESULTS: Staffing transitioned to a team of neurosurgeons, neurointensivists, neurohospitalists, and midlevel practitioners. Order sets, protocols, and pathways were developed. Quality improvements were observed for craniotomy and cranioplasty surgical site infections, ventriculitis, coagulopathy reversal, and decompressive hemicraniectomy rates for stroke. Case volume increased 73%, yet craniotomy hospital days decreased from 2768 in 2008 to 2599 in 2017 because of reduced length of stay. We accommodated service line growth without hospital expansion or case backlogs. With an average California hospital day rate of $3341, the improved length of stay decreased costs by $14,666,990/y. We also present outcomes data, including craniotomy indications, operative timing, complications, functional outcomes, delays in discharge, and discharge destinations using the craniotomy discharge summary. CONCLUSION: Multidisciplinary teams, protocols, and pathways reduced craniotomy complication rates, improved hospital length of stay by 63%, reduced costs, and increased professional collegiality and satisfaction. A searchable craniotomy discharge summary is an important tool for continuous monitoring of quality and efficiency of care.

Diagnosis, Classification, and Management of Fourth Ventriculomegaly in Adults: Report of 9 Cases and Literature Review.

OBJECTIVE: An enlarged fourth ventricle, otherwise known as fourth ventriculomegaly (4th VM), has been reported previously in the pediatric population, yet literature on adults is scant. We report our experience with 4th VM in adults over an 11-year period and review the literature. MATERIALS AND METHODS: This was a retrospective chart review of adult patients with the diagnosis of 4th VM admitted to the intensive care unit in a tertiary care center. RESULTS: Nine patients were identified with 4th VM. Most presented with symptoms in the posterior fossa. Five cases were related to previous shunting and the underlying neurosurgical diseases, and average time interval to develop symptoms was 5.3 years. We divided our cases into primary, acquired, and degenerative based on the pathophysiology involved. Treatments included extended subzero cerebrospinal fluid diversion using a frontal external ventricular drain followed by low-pressure shunt revision, endoscopic third ventriculostomy, suboccipital decompression, and fourth ventricular catheter placement. Literature review identified additional published cases, and there were no reports of a formal classification scheme or treatment algorithm. CONCLUSIONS: This case series illustrates a narrow spectrum of etiologies associated with 4th VM in adults. We propose a simple classification scheme dividing 4th VM into 3 categories: primary, acquired, and degenerative. We recommend a stepwise treatment approach starting with extended subzero cerebrospinal fluid diversion followed by shunting for symptomatic primary and acquired 4th VM. Lower success rates and greater morbidity are associated with rescue procedures such as fourth ventricle drainage catheters, endoscopic third ventriculostomies, and skull base decompression.

Spinal Cord Herniation After Cervical Corpectomy with Cerebrospinal Fluid Leak: Case Report and Review of the Literature.

BACKGROUND: Spinal cord herniation (SCH) is rare, is mostly idiopathic, and occurs predominantly in the thoracic spine. SCH is less common in the cervical spine and has been reported after posterior cervical spine surgery associated with the development of pseudomeningoceles. Two cases of SCH have been reported after anterior cervical corpectomies for ossified posterior longitudinal ligament with cerebrospinal fluid (CSF) leaks. We report the third such case, but the first in a patient without ossified posterior longitudinal ligament (degenerative disc disease and pseudarthrosis). CASE DESCRIPTION: A 56-year-old woman presented with bilateral arm pain and weakness. She had undergone 3 previous anterior cervical spine surgeries at an outside medical center with the most recent 7 years ago with C5 and C6 corpectomies and fusion with a persistent CSF leak. Magnetic resonance imaging and computed tomography myelography showed spinal cord herniation through the mesh cage at C6. The patient underwent a redo C5 and C6 corpectomy with untethering of the spinal cord. The patient was asymptomatic 2 years later. CONCLUSIONS: This is the first reported case of anterior cervical SCH in a patient without ossified posterior longitudinal ligament after multiple anterior cervical fusions including a cervical corpectomy for pseudarthrosis with a CSF leak. We hypothesize that persistent CSF leak causes a pressure gradient across the dura mater through the cage to the lower pressure in the retropharyngeal space, which led to herniation of the spinal cord into the anterior cage. We review the literature and discuss the treatment choices for anterior cervical SCH.

Management and outcomes of malignant posterior reversible encephalopathy syndrome.

INTRODUCTION: Recognition of severe forms of posterior reversible encephalopathy syndrome (PRES) has improved. Management of these patients remains challenging, particularly in patients with the combination of edema and hemorrhage. METHODS: A prospective inpatient neuro-intensive care database was queried for patients with PRES. Malignant PRES was diagnosed by clinical assessments (GCS less than 8 and clinical decline despite standard medical management for elevated intracranial pressure) and radiographic criteria (edema with associated mass effect; brain hemorrhage exerting mass effect; effacement of basal cisterns, transtentorial, tonsillar, or uncal herniation). Malignant PRES was defined as: radiology studies consistent with PRES; GCS less than 8; and clinical decline despite standard elevated intracranial pressure management. RESULTS: Five cases were identified over a 4 year interval. The following contributing conditions were also present: chemotherapy (1), systemic lupus erythematosis (2), pregnancy (1), and methamphetamines (1). Neurocritical care interventions included: hyperosmolar therapy (5), anticonvulsants (5), management of coagulopathy (5), and ventilatory support (5). Neurosurgical interventions included: craniectomy (5), hematoma evacuation (3), and external ventricular drain (4). Brain biopsy was performed in 5 patients and was negative for vasculitis, demyelinating disease, tumor, or infection. Cyclophosphamide was administered to the two patients with SLE. With long-term follow up, all patients achieved good functional outcomes (modified Rankin score 1-2). CONCLUSION: In contrast to historical reports of high mortality rates (16-29%) for severe and hemorrhagic PRES variants, we had no fatalities and observed favorable functional outcomes with intracranial pressure monitoring and craniectomy for malignant PRES cases who fail medical ICP management.

Lower complication rates for cranioplasty with peri-operative bundle.

BACKGROUND: The overall benefits of craniectomy must include procedural risks from cranioplasty. Cranioplasty carries a high risk of surgical site infections (SSI) particularly with antibiotic resistant bacteria. The goal of this study was to measure the effect of a cranioplasty bundle on peri-operative complications. METHODS: The authors queried a prospective, inpatient neurosurgery database at Kaiser Sacramento Medical Center for craniectomy and cranioplasty over a 7 year period. 57 patients who underwent cranioplasties were identified. A retrospective chart review was completed for complications, including surgical complications such as SSI, wound dehiscence, and re-do cranioplasty. We measured cranioplasty complication rates before and after implementation of a peri-operative bundle, which consisted of peri-operative vancomycin (4 doses), a barrier dressing through post-operative day (POD) 3, and de-colonization of the surgical incision using topical chlorhexidine from POD 4 to 7. RESULTS: The rate of MRSA colonization in cranioplasty patients is three times higher than the average seen on ICU admission screening (19% vs. 6%). The cranioplasty surgical complication rate was 22.8% and SSI rate was 10.5%. The concurrent SSI rate for craniectomy was 1.9%. Organisms isolated were methicillin-resistant Staphylococcus aureus (4), methicillin-sensitive S. aureus (1), Propionibacterium acnes (1), and Escherichia coli (1). Factors associated with SSI were peri-operative vancomycin (68.6% vs. 16.7%, p=0.0217). Complication rates without (n=21) and with (n=36) the bundle were: SSI (23.8% vs. 2.8%, p=0.0217) and redo cranioplasty (19% vs. 0%, p=0.0152). Bundle use did not affect rates for superficial wound dehiscence, seizures, or hydrocephalus. CONCLUSIONS: The cranioplasty bundle was associated with reduced SSI rates and the need for re-do cranioplasties.

Subarachnoid hemorrhage due to retained lumbar drain.

Intrathecal spinal catheters (lumbar drains) are indicated for several medical and surgical conditions. In neurosurgical procedures, they are used to reduce intracranial and intrathecal pressures by diverting CSF. They have also been placed for therapeutic access to administer drugs, and more recently, vascular surgeons have used them to improve spinal cord perfusion during the treatment of thoracic aortic aneurysms. Insertion of these lumbar drains is not without attendant complications. One complication is the shearing of the distal end of the catheter with a resultant retained fragment. The authors report the case of a 65-year-old man who presented with a subarachnoid hemorrhage due to the migration of a retained lumbar drain that sheared off during its removal. To the best of the authors' knowledge, this is the first case of rostral migration of a retained intrathecal catheter causing subarachnoid hemorrhage. The authors review the literature on retained intrathecal spinal catheters, and their findings support either early removal of easily accessible catheters or close monitoring with serial imaging.