Chordoid Glioma with Psychosis: Case Report.

OBJECTIVE: A rare, low-grade tumor found in the hypothalamus and anterior third ventricle, a chordoid glioma presents a challenge to neurosurgeons: Its successful resection is complicated by its inconvenient location. CASE DESCRIPTION: A 42-year-old male patient presented with a 1-year history of major depressive disorder, with psychotic features associated with generalized tonic-clonic seizures. Brain magnetic resonance imaging (MRI) with contrast revealed a suprasellar mass extending into the third ventricle To resect the lesion, an interhemispheric transcallosal transventricular subfornical approach was used. Pathology revealed a chordoid glioma. The patient had a complicated post-operative period that included the development of neurogenic diabetes insipidus, followed by intractable hyponatremia and death (caused by malignant brain edema). CONCLUSION: A chordoid glioma is a rare neoplasm that, in 2000, was incorporated into the World Health Organization (WHO) classification of central nervous system tumors. Due to its rarity, it is seldom considered in the differential diagnosis of suprasellar masses. Moreover, its unusual presentation and difficult location present a challenge for surgical and medical management.

Circumferential Stabilization of the Thoracolumbar Junction Via Posterior-Only Approach for the Management of Burst Fractures.

OBJECTIVE: The management of thoracolumbar burst fractures often includes combined anterior/posterior approaches with prolonged operative time and complications. The transpedicular approach offers a posterior only approach with circumferential reconstruction and decompression. We aim to present the experience of a single center in the management of thoracolumbar burst fractures using a posterior-only approach for circumferential stabilization and report on this technique's effectiveness in restoring the alignment of the thoracolumbar junction. METHODS: A case review of the medical records of patients admitted to the adult neurosurgery service (from January 2011 through June 2014) with traumatic non-pathological thoracolumbar burst fractures and subsequently treated with a transpedicular corpectomy (including the placement of an expandable cage) was performed, retrospectively. RESULTS: A total of 20 patients underwent a posterior transpedicular corpectomy consisting of anterior column reconstruction using an expandable cage with supplementary posterior fixation within 72 hours of injury. The average pre-operative canal compromise was 69%. The average pre-operative kyphotic angle was 21.6°. The average post-operative kyphotic angle was 5.15°, with an average correction of 16.45°. There were 11 patients with pre-operative neurological compromises, of which patients, 8 experienced variable degrees of recovery. The average operating time was 410.5 minutes (range, 240-550 min). The average blood loss was 880 mL (range, 650-1500). Three patients experienced complications during surgery; 1 patient died. CONCLUSION: The transpedicular approach for circumferential reconstruction and stabilization provides an alternative technique for the management of thoracolumbar fractures, having an acceptable risk and the associated lower morbidity of a posterioronly approach.

Post-operative seizures after burr hole evacuation of chronic subdural hematomas: is prophylactic anti-epileptic medication needed?

INTRODUCTION: There are limited data with regards to the associated risk of post-operative seizures in patients with surgically treated chronic subdural hematomas (CSDHs). The use of anti-epileptic drugs (AEDs) is associated with significant side effects. METHODS: A retrospective chart review was performed on patients operated via burr hole for CSDH in our institution from 2004 to 2013. Post-operative seizures at 1-year follow-up were identified. Demographic data, medical history, and imaging characteristics were recorded. RESULTS: A total of 220 patients were included in the study. Post-operative seizures occurred in 2.3%. The mean time of onset of seizures was 8.4 days. No difference in age and gender between seizing and non-seizing groups was identified p > 0.05. Mean midline shift was 4.6 mm in seizing group vs. 4.2 mm in non-seizing group, p > 0.05. Mean thickness was 14.6 mm in patients without post-operative seizures and 18.4 mm in patients with post-operative seizures, p > 0.05. There was no significant difference in post-operative seizure incidence related to the side or location of the CSDHs. CONCLUSIONS: The incidence of post-operative seizures in patients with CSDH evacuated via burr holes was low. Prophylactic AEDs should not be routinely administered if no other risk factor for seizure exists. Demographic and clinical factors did not appear to influence post-operative seizures.

Neurosurgical Injuries Associated With the Use of Personal Watercrafts.

INTRODUCTION:  A personal watercraft is widely used for recreation on coastlines, rivers, and lakes. This study aimed to identify the spectrum of neurosurgical injuries related to personal watercraft accidents in Puerto Rico. METHODS: A retrospective study was performed utilizing the University of Puerto Rico neurosurgery database to identify patients who had been consulted to the neurosurgery service from 2005 to 2023 due to a personal watercraft-related neurosurgical injury. For each identified patient, basic demographics, injuries received, Glasgow coma scale score at arrival, American Spinal Injury Association impairment scale grade, surgery performed, and outcome upon discharge using the modified Rankin scale (mRS) score were collected. Descriptive statistics were used to report frequency and mean values. RESULTS: Our service evaluated 11 patients with a personal watercraft-related neurosurgical injury diagnosis during the study period. The mean age of the patients was 35 (± 9). Around 82% of the patients were males. Ejection from the personal watercraft was the mechanism of the trauma in 73% of the patients. Three patients were impacted by a personal watercraft. There were seven spinal injuries and four brain injuries. Among the spinal injured patients, two had neurological deficits. None of the patients with brain trauma required urgent surgery; however, three arrived intubated. Two of them showed signs of diffuse axonal injuries on the head CT scan, while the other had multiple brain contusions. Upon discharge, 70% of the patients had a mRS grade of 0-3. CONCLUSIONS: Personal watercraft accidents causing significant neurological injuries to the brain and spine are infrequent. Injuries were more prevalent among male patients in their thirties. Most patients showed good outcomes when discharged from the hospital. Moderate to severe disability occurred more frequently among spinal injured patients due to residual deficits requiring assistance for ambulation and activities of daily living.

Use of Recombinant Human Bone Morphogenetic Protein-2 After Anterior Cervical Corpectomy and Fusion for the Treatment of Vertebral Osteomyelitis.

OBJECTIVE: To report the operative outcomes after treating vertebral osteomyelitis patients with an anterior cervical corpectomy and fusion procedure using recombinant human bone morphogenetic protein-2 (rhBMP-2) as graft material. METHODS: A retrospective review of electronic medical records of 26 adult patients who underwent an anterior cervical corpectomy and fusion procedure for cervical osteomyelitis using rhBMP-2 at the University of Puerto Rico University District Hospital was performed. Indication, preoperative laboratory results, levels of corpectomy, preoperative American Spinal Injury Association Impairment Scale (ASIA) score, complications, fusion evaluation at 12 months, and ASIA score at 12 months were reviewed. RESULTS: For the cohort of patients, mean age was 47 ± 13 years and 65% were male. Spinal instability was present in 54%. The levels of corpectomy were: 1 level in 2 cases, 2 levels in 15 cases, 3 levels in 8 cases, and 5 levels in 1 case. Four patients had complications and, of these, 2 experienced dysphagia. The fusion rate was 100% and no reoperations were performed. An improvement in ASIA score was seen for 54% patients at 12-month follow-up. CONCLUSIONS: This study demonstrates a fusion rate of 100% with no reoperations reported. Recombinant human bone morphogenetic protein-2 could be considered and further researched as grafting material for anterior cervical corpectomy and fusion procedures in cervical osteomyelitis patients.

Cervical Intramedullary Spinal Cord Abscess Secondary to Discitis and Osteomyelitis in an Immunocompromised Patient.

Intramedullary spinal cord abscess is a rare neurological condition, not commonly suspected and often misdiagnosed. Even after a prompt diagnosis and treatment, most patients persist with permanent neurological deficits. In adults, factors such as immunocompromised, intravenous drug use, endocarditis, and sepsis could be associated with its development. In this study, we present the case of a 63-year-old male patient who developed a chronic cervical intramedullary spinal cord abscess after being treated for multiple abscesses in the paravertebral and psoas muscles. A diagnosis of cervical intramedullary spinal cord abscess secondary to osteomyelitis and discitis was made. He underwent a two-stage cervical surgery, with drainage of the abscess, spinal stabilization, and intravenous antibiotics. Although rare, vertebral osteomyelitis and discitis may be related to its development. Early diagnosis, prompt abscess drainage, and appropriate antibiotic therapy are of utmost importance to improve prognosis and minimize the long-term sequelae and complications of permanent neurological deficits.

Gamma Knife radiosurgery for a recurrent craniocervical junction solitary fibrous tumour.

Spinal solitary fibrous tumour (SFT) is an uncommon tumour with few cases reported in the literature. It rarely originates at the craniocervical junction. To our knowledge, only eight cases of spinal SFT located at the craniocervical junction have been reported in the literature. We presented a patient with a craniocervical junction SFT and discussed its clinical presentation, radiological features, pathology, management and outcome. This was the first patient reported in the literature with a recurrent craniocervical junction SFT treated with Gamma Knife radiosurgery. The treatment reduced the tumour volume by more than 85% within 12 months.

Prognosis and Outcome of Cervical Primary Extraosseous Intradural Extramedullary Ewing Sarcoma: A Systematic Review.

Primary spinal extraosseous Ewing sarcoma (ES) is a rare mesenchymal tumor characterized by high malignancy, occurring in a few patients with ES. The occurrence of this tumor in the intradural extramedullary spinal region is infrequent. This systematic review examines primary extraosseous intradural extramedullary ES in the cervical region to provide specific outcomes and evaluate the role of adjuvant chemoradiation in overall prognosis. A systematic review was conducted to identify all cervical primary extraosseous intradural extramedullary ES reported in the literature. The search included the databases of PubMed, Google Scholar, Medline, Embase, and Scopus from inception to June 2021. Inclusion criteria include a reported death outcome or a minimum one-year follow-up. Our search retrieved 21 articles that involved the cervical spine, but only 11 cases met the inclusion criteria. Of the nine patients who demonstrated disease progression, six experienced local failure, two had distant craniospinal axis failure, and one had systemic metastases. Five patients died of the disease at a median of 11 months after diagnosis. Our analysis showed a one-, two-, and five-year progression-free survival (PFS) of 36.4%, 36.4%, and 12.1%, respectively. The one-, two-, and five-year overall survival rates were 72.7%, 62.3%, and 46.8%, respectively. Three of the five (60%) patients who died received craniospinal radiotherapy. Of the six patients who survived, two received craniospinal radiotherapy (33%), and one received whole spine radiotherapy (17%). This review showed that patients with cervical primary extraosseous intradural extramedullary ES had poor progression-free survival and overall survival rates. The addition of adjunct craniospinal radiotherapy did not improve the prognosis of these patients.

Vagus nerve stimulation for intractable seizures in children: the University of Puerto Rico experience.

OBJECTIVE: Vagus nerve stimulation (VNS) is considered an alternative treatment for patients with medically refractory epilepsy who are not candidates for resective surgery. It consists of intermittent electrical stimulation of the left vagus nerve in the neck. Such stimulation has been demonstrated to be efficacious, safe, and well tolerated, offering these patients another option for seizure control. The aim of this study was to evaluate the experience of VNS at the University of Puerto Rico, and to examine demographic data, types of seizures, and seizure-control outcomes among treated subjects. This study is the first account of VNS in a pediatric population living in the Caribbean area. METHODS: A retrospective analysis of 13 patients treated at the University Pediatric Hospital in San Juan, Puerto Rico, was undertaken. Different types of seizures were identified and managed. RESULTS: The mean age at implantation was 12 years; 77% of patients were female. The most common type of seizure treated was generalized tonic-clonic (24%), followed by complex partial (23%). Sixty-nine percent of patients demonstrated a reduction in monthly seizure frequency. Ninety-three percent of caregivers reported improvements in alertness and communication. CONCLUSION: Vagus nerve stimulation is a safe and effective way to treat medically refractory epilepsy and should be considered as a non-pharmacological treatment for select patients with medically refractory epilepsy.

Pediatric brain tumors in Puerto Rico.

OBJECTIVE: To determine the frequency of pediatric brain tumors treated at the University Pediatric Hospital of Puerto Rico over a 6-year period and examine the demographic data and tumor histology of patients in different age groups. METHODS: A retrospective study was undertaken at the University Pediatric Hospital. We included patients with brain tumors that had been newly diagnosed during the period covering from January 2002 to December 2007. All cases were analyzed by age, gender, histologic diagnosis, and affected area. RESULTS: One hundred thirty-six patients were included in the study. Overall, males were more frequently affected than were females. Children in the 1 to 4 years old age group had the highest number of newly diagnosed brain tumors. Regarding anatomic location, supratentorial tumors were more frequent than were infratentorial tumors. The most common single tumor was the pilocytic astrocytoma (WHO grade I), representing 31% of the total pediatric brain tumors. CONCLUSION: Our results provide an objective platform for further epidemiological studies and for the development of local health strategies for the timely diagnosis and treatment of the most common pediatric tumors in Puerto Rico.

Lemierre syndrome leading to an ischaemic stroke and malignant cerebral oedema.

Lemierre syndrome is an often misdiagnosed disease caused by an anaerobic bacterial infection that produces thrombophlebitis of the internal jugular vein and septic metastasis to distal organs, especially the lungs. Carotid stenosis or thrombosis is a rare complication. We present a patient with Lemierre syndrome who developed malignant cerebral oedema secondary to an ischaemic stroke which required a decompressive craniectomy.

Rare sacral extradural grade II ependymoma: a comprehensive review of literature.

Sacral spinal cord ependymoma is an uncommon pathology. Most of the reported cases are consistent with a myxopapillary ependymoma histopathologic subtype. Non-myxopapillary ependymomas rarely occur in the sacral region. Most lesions are intradural; however, rare extradural cases can occur. We present the case of a 46-year-old female patient diagnosed with a grade II sacral extradural ependymoma, emphasising the importance of an interdepartmental case approach for diagnosis and management. Even though grade II ependymomas are considered low grade, the potential for recurrence and metastatic disease has been reported. There are no treatment guidelines for these rare tumours besides gross total resection.

Prevention of Surgical Site Infection in Lumbar Instrumented Fusion Using a Sterile Povidone-Iodine Solution.

BACKGROUND: Surgical site infection (SSI) is a well-documented complication in patients who undergo posterior spine instrumentation with most studies reporting an incidence of 1%-12%. Some studies have documented that a diluted sterile povidone-iodine (PVI) solution can be safely used in posterior spinal fusion surgeries as an antiseptic; in this study, we analyzed its effectiveness in reducing SSI. METHODS: This retrospective study consisted of consecutive patients who underwent elective posterior lumbar instrumentation performed by a single surgeon from 2016 to 2019. In the first 134 patients, wounds were irrigated before arthrodesis and closure with 1 L of 0.9% normal saline solution; in the subsequent 144 patients, wound irrigation was with a solution of 35 mL of sterile 10% PVI. Both groups were analyzed to determine if wound irrigation with sterile PVI solution decreased SSIs. RESULTS: There were 9 (6.7%) SSIs in the 0.9% normal saline solution group versus 1 (0.7%) SSI in the PVI group (P = 0.008). PVI solution had a relative risk for SSI of 0.093 (P = 0.008) and an adjusted odds ratio of 0.113 (P = 0.05). Increased body mass index and posterolateral spine fusion with laminectomy were significant risk factors for SSI (P = 0.04 and P = 0.030, respectively). CONCLUSIONS: Wound irrigation with PVI solution significantly reduced SSI in elective posterior lumbar instrumentation cases. Subgroup analysis provided significant results to recommend use of PVI solution for SSI prevention, particularly in overweight and obese patients. We also recommend its use in patients with risk factors for SSI, such as longer operative time and unintended durotomy.

Endoscopic third ventriculostomy: a surgeon's experience.

INTRODUCTION: Endoscopic third ventriculostomy (ETV) is considered an alternative treatment for certain types ofhydrocephalus. Depending on patient's age and etiology of hydrocephalus, it carries a success rate of around 90%. However, as in any surgical procedure, inherent risks are present and a risk-benefit analysis must be done prior to selecting patients for this intervention. OBJECTIVE: To evaluate retrospectively the experience of ETV at the University of Puerto Rico and examine the etiological factors, demographic data and symptoms among the Puerto Rico population. This study represents the data of one neurosurgeon and is the first account of endoscopic third ventriculostomy as a mode of treatment in the Caribbean area. METHODS: Retrospective analysis was undertaken of 29 patients treated at the University Pediatric Hospital (UPH) and University District Hospital (UDH) in San Juan was undertaken Different etiologies of hydrocephalus were identified and managed. RESULTS: The most common indication for ETV was aqueductal stenosis (59%) with male predominance (55%). Also, the most common population treated were adults (72%) and the most common symptom presented were headaches (52%) and gait disturbances (43%). CONCLUSIONS: Endoscopic third ventriculostomy is a safe and effective way to treat hydrocephalus and should be considered as first choice of treatment for certain patients with hydrocephalus unless otherwise contraindicated.

Efficacy of Hydromer-Coated and Antibiotic- Impregnated Shunt Systems in Reducing Early Shunt Infections in the Pediatric Population.

OBJECTIVE: Shunt infection is the most common complication following a Cerebrospinal fluid (CSF) diversion procedure with devastating consequences. This study analyzes the efficacy of different shunt systems in reducing early shunt infections in the pediatric population. METHODS: Retrospective case study analysis of 177 pediatric patients with hydrocephalus de novo shunted using hydromer-coated (HC) shunt systems, antibiotic-impregnated (AI) shunt systems and standard non impregnated shunt systems was performed and compared for the incidence of shunt infection in the early postoperative period. RESULTS: Group A consisted of standard shunt systems with 63 patients, Group B were HC shunt systems with 67 patients and group C consisted of 47 patients with antibiotic-impregnated shunt systems. Mean age in Group A was 1.36 +/- 3.36 years Mean age in Group B was 2.32 +/- 4.69 years. Mean age in Group C: 0.64 +/- 1.70 years. In terms of shunt infections, HC group had 4 shunt infections (6.25%), as compared to the control group, where 7 patients (10.45%) had infections. The AI group had 1 infection (2.13%). When comparing HC systems versus Standard Non-Impregnated There were 3 shunt malfunction in Group A (4.8%), 2 shunt malfunction in group B (3.3%) and 0 shunt malfunction in Group C (0%). CONCLUSION: Hydromer-coated shunt systems and antibiotic-impregnated shunt system represent a superior alternative to standard shunt systems for the reduction of shunt infection in the early post operative period.

Time of Surgery in the Outcome of Cervical Spinal Cord Injury: the University of Puerto Rico Experience.

OBJECTIVE: The purpose of this study was to determine the effect of the timing of surgery on the neurological function of patients with a cervical spinal cord injury. METHODS: Retrospectively, an analysis was done of patients who underwent decompression and/or spinal cord stabilization surgeries from 2010 through 2014 for cervical trauma. All patients were older than 18 years of age, had had surgery at our facility, and had made at least 1 follow-up visit. American Spinal Injury Association (ASIA) Impairment Scale (AIS) scores were compared for patients who underwent early surgeries (less than 72 hours after trauma) and for those who underwent late surgeries (more than 72 hours after trauma). RESULTS: There were a total of 107 patients. Sixty-two patients had spinal cord injuries. The average age was 38.6 years, and 84% of the participants were male. The most common mechanism of trauma was motor vehicle accident. Twenty-nine percent of the patients developed neurogenic shock and 27% experienced respiratory failure during the first week after admission. Seventeen patients died during the study period. A multivariate analysis of AIS score improvement revealed that the only significant factor was incomplete neurological injury. There was no significant difference in the percentage of patients that improved with early surgery compared to that of those that improved after late surgery. CONCLUSION: Traumatic cervical spinal cord injury is associated with high mortality and morbidity. Early surgery was not associated with an improved neurological outcome at long-term follow-up. The benefit of early surgery was seen only in terms of decreasing each patient's length of hospital stay.

Cavernous Malformation of a Thoracic Spinal Nerve Root: Case Report and Review of Literature.

Intradural extramedullary spinal cavernous malformations (CMs) remain the least common variant of these lesions and can originate from the inner surface of the dura mater, the pial surface of the spinal cord, and the blood vessels in the spinal nerves. Root-based-only extramedullary CMs are very rare in the thoracic region with only four cases reported. We present a case of 56-year-old male with 1-year progression of lower extremities weakness. Magnetic resonance imaging demonstrated a hyperintense lesion in the upper thoracic region. Surgical exploration revealed a CM with origin in the second thoracic nerve root with gross total resection. Histopathological examination confirmed a CM. The patient had complete recovery of neurological function at 3 months interval. Intradural extramedullary CM is extremely rare entity that must be considered in the differential diagnosis of intradural extramedullary lesions. Surgical resection is the treatment of choice to prevent further neurological damage.

Effect of the covalent modification of horseradish peroxidase with poly(ethylene glycol) on the activity and stability upon encapsulation in polyester microspheres.

Encapsulation of proteins in polyester microspheres by coacervation methods frequently causes protein inactivation and aggregation. Furthermore, an often-substantial amount of the encapsulated proteins is released within the first 24 h from the microspheres. To overcome these problems poly(ethylene glycol) (PEG) was employed as excipient and protein-modifying agent. The model protein horseradish peroxidase (HRP) was chemically modified or co-lyophilized with PEG of differing molecular weights, namely PEG(5000), PEG(20000), and PEG(40000). The lyophilized preparations were encapsulated in poly(D,L-lactide-co-glycolic) acid (PLGA) microspheres by a coacervation method. Covalent modification of HRP with PEG increased the encapsulation efficiency (EE) from 83% to about 100% while PEG when used as an excipient reduced the EE. Encapsulation caused aggregation of ca. 5% of non-modified HRP and the residual specific activity was only 57%. Covalent modification with PEG reduced HRP aggregation to less than 1% and improved its residual activity to more than 95%. When PEG was used as excipient similar results were found with respect to a reduction in encapsulation-induced aggregation, but no more than 80% of residual activity was obtained even for the best formulation after encapsulation. It was also found that covalent modification of HRP with PEG substantially reduced the unwanted initial "burst" release observed during the initial 24 h of in vitro release from about 70% to 23%. Furthermore, HRP activity and stability were also improved during in vitro release for HRP-PEG conjugates. The data show that covalent modification of proteins with PEG might be useful to improve protein stability during coacervation encapsulation and subsequent release as well as to increase EE and reduce the burst release.

Acute adrenal insufficiency in cervical spinal cord injury.

BACKGROUND: Adequate adrenal response is fundamental for the maintenance of physiological homeostasis in the setting of trauma and severe illness. Patients with neurogenic shock are at risk of severe consequences if adrenal insufficiency (AI) is not rapidly identified and treated. OBJECTIVE: To analyze the incidence of AI in patients with acute cervical spinal cord injury and its effect on in-hospital complications. METHODS: The medical records of patients older than 18 years who were admitted to the adult neurosurgery service at the University District Hospital as the result of neurogenic shock after acute cervical spinal cord injury from January 2004 to December 2009 were reviewed retrospectively. RESULTS: One hundred ninety-nine patients were admitted with acute cervical spinal cord injury. A total of 37 patients met the pre-established criteria for neurogenic shock. The incidence of AI in patients with neurogenic shock was 22%. The average random cortisol was 9.3 µg/dL in patients with AI versus 29.2 µg/dL in non-AI. The presence of AI was positively correlated with complications and an increase in the risk of intubation (P = 0.01 and P = 0.002). The 30-day mortality rate in patients with AI was 13% compared with the 3% in the non-AI group (P = 0.39). CONCLUSIONS: Adrenal insufficiency is a poorly recognized complication in patients with acute cervical spinal cord injury and its aggressive treatment is of utmost importance to avoid further neurological injury.

Structure of poly(ethylene glycol)-modified horseradish peroxidase in organic solvents: infrared amide I spectral changes upon protein dehydration are largely caused by protein structural changes and not by water removal per se.

Fourier transform infrared (FTIR) spectroscopy has emerged as a powerful tool to guide the development of stable lyophilized protein formulations by providing information on the structure of proteins in amorphous solids. The underlying assumption is that IR spectral changes in the amide I and III region upon protein dehydration are caused by protein structural changes. However, it has been claimed that amide I IR spectral changes could be the result of water removal per se. Here, we investigated whether such claims hold true. The structure of horseradish peroxidase (HRP) and poly(ethylene glycol)-modified HRP (HRP-PEG) has been investigated under various conditions (in aqueous solution, the amorphous dehydrated state, and dissolved/suspended in toluene and benzene) by UV-visible (UV-Vis), FTIR, and resonance Raman spectroscopy. The resonance Raman and UV-Vis spectra of dehydrated HRP-PEG dissolved in neat toluene or benzene were very similar to that of HRP in aqueous buffer, and thus the heme environment (heme iron spin, coordination, and redox state) was essentially the same under both conditions. Therefore, the three-dimensional structure of HRP-PEG dissolved in benzene and toluene was similar to that in aqueous solution. The amide I IR spectra of HRP-PEG in aqueous buffer and of dehydrated HRP-PEG dissolved in neat benzene and toluene were also very similar, and the secondary structure compositions (percentages of alpha-helices and beta-sheets) were within the standard error the same. These results are irreconcilable with recent claims that water removal per se could cause substantial amide I IR spectral changes (M. van de Weert, P.I. Haris, W.E. Hennink, and D.J. Crommelin. 2001. Anal. Biochem. 297:160-169). On the contrary, amide I IR spectral changes upon protein dehydration are caused by perturbations in the secondary structure.