Addressing a national crisis: the spine hospital and department's response to the COVID-19 pandemic in New York City.

In a very brief period, the COVID-19 pandemic has swept across the planet leaving governments, societies, and healthcare systems unprepared and under-resourced. New York City now represents the global viral epicenter with roughly one-third of all mortalities in the United States. To date, our hospital has treated thousands of COVID-19 positive patients and sits at the forefront of the United States response to this pandemic. The goal of this paper is to share the lessons learned by our spine division during a crisis when hospital resources and personnel are stretched thin. Such experiences include management of elective and emergent cases, outpatient clinics, physician redeployment, and general health and wellness. As peak infections spread across the United States, we hope this article will serve as a resource for other spine departments on how to manage patient care and healthcare worker deployment during the COVID-19 crisis.

Diagnosis of brain death by common carotid artery velocity waveform analysis.

In addition to neurologic criteria, some test of cessation of brain blood flow is recommended before diagnosing "brain death." Cerebral arteriography, radionuclide scintigraphy, and contrast computed axial tomography, though reliable, possess significant practical limitations. Analysis of the dimensions and contours of common carotid Doppler velocity tracings of brain-dead patients has identified qualitative and quantitative differences not only from normal subjects, but also from patients with complete atheromatous carotid occlusion and from those unconscious after brain injury. Though accurate separation was initially made using computer-assisted classification function analysis, a simplified algorithmic approach using only three velocity waveform variables has been developed without loss of accuracy. The speed, simplicity, portability, and inexpensiveness of this approach commend its use.

Hand preferences of rhesus monkeys on differing tasks.

In a replication study, monkeys were tested for hand preference on three differing tasks: simple reaching for food presented on a board, choice of hand during a visual discrimination task and retrieval of food pellets from a row. Both laterality and degree of hand preference correlated significantly on two of the three tasks. Extremely little correlation was found across the other task combinations. Consistency of hand preference was greater within repetitions of a task than between any two tasks. The implication of these findings upon the search for a cerebral dominance underlying hand preference in the monkey is discussed.

In vitro hypoxia and excitotoxicity in human brain induce calcineurin-Bcl-2 interactions.

Although pathogenesis of neuronal ischemia is incompletely understood, evidence indicates apoptotic neuronal death after ischemia. Bcl-2, an anti-apoptotic and neuroprotective protein, interacts with calcineurin in non-neuronal tissues. Activation of calcineurin, which is abundant in the brain, may play a role in apoptosis. Using co-immunoprecipitation experiments in biopsy-derived, fresh human cortical and hippocampal slices, we examined possible interactions between calcineurin and Bcl-2. Calcineuin-Bcl-2 interactions increased after exposure in vitro to excitotoxic agents and conditions of hypoxia/aglycia. This interaction may shuttle calcineurin to substrates such as the inositol-1,4,5-tris-phosphate receptor because under these experimental conditions interactions between calcineurin and inositol-1,4,5-tris-phosphate receptor also increased. A specific calcineurin inhibitor, FK-520, attenuated insult-induced increases in calcineurin-Bcl-2 interactions and augmented caspase-3 like activity. These data suggest that Bcl-2 modulates neuroprotective effects of calcineurin and that calcineurin inhibitors increase ischemic neuronal damage.

Cutaneous scar at anterior hair line in mother and child with associated frontal bone defect in child.

A large frontal bone defect underlying a "V" shaped scar was noted in a newborn male whose mother had an identical "V" shaped scar at the same location in the anterior hairline. Both had hypertelorism and short palpebral fissures. The mother had no radiographic evidence of skull defect and neither mother nor child had other cutaneous or skeletal anomalies. Cranioplasty was performed on the child using the remaining frontal bones with an excellent cosmetic result. Biopsy performed at operation documented scar tissue extending through the dermis and underlain by thickened dura. Mother and child appear to have a variant form of aplasia cutis congenita, an autosomal dominant trait with wide variation in expression.

Persistence of primate hand preference despite initial training to the contrary.

Forty-six stumptail monkeys were tested for hand preference on a simple reaching task. Initial repeated reaches with the hand chosen for the first reach went unrewarded. All reaches following and including the earliest reach with the opposite hand were rewarded and were used to calculate overall hand preference for the task. A significant majority of the animals continued to prefer the hand initially used in unrewarded trials rather than the hand first receiving a reward. These results suggest that monkeys are predisposed to choose the hand preferred for a new task.

Cerebral glucose utilization after aversive conditioning and during conditioned fear in the rat.

Regional cerebral glucose utilization (rCMRglu) was studied in rats with and without previous aversive conditioning. Four groups of rats were studied. Two groups of rats were aversely conditioned by placing them in a shock chamber (conditioned stimulus) where they received random footshocks. The two remaining groups were placed in the shock chamber but not conditioned. Regional CMRglu and systemic parameters (heart rate, mean arterial blood pressure (MABP), blood gases and pH, plasma catecholamines, and plasma glucose) were measured in unconditioned and conditioned rats in the presence and in the absence of the conditioned stimulus. The changes in rCMRglu described below appeared to be global and not limited to specific regions. Results are as follows: (1) transferring unconditioned rats to the shock chamber had no significant effect on rCMRglu even though the systemic parameters indicated a stress response. It appears that stress capable of inducing changes in heart rate, MABP, and plasma catecholamines is not necessarily accompanied by increases in cerebral glucose utilization. (2) Conditioned rats not exposed to the shock chamber at the time rCMRglu was measured had decreased rates of rCMRglu compared to rats that were not conditioned. Except for plasma epinephrine, which increased after conditioning, systemic parameters were not affected. (3) Conditioned fear, elicited by transferring conditioned rats to the shock chamber, increased rCMRglu when compared to a control group that was conditioned to footshock using the same paradigm but not exposed to the shock chamber at the time rCMRglu was measured. The systemic parameters indicated a stress response in conditioned rats transferred to the shock chamber.(ABSTRACT TRUNCATED AT 250 WORDS)

Intradural lumbar disk fragment with ring enhancement on MR.

Intradural extension of a herniated intervertebral disk, an unusual complication of a common disease, may mimic an intradural tumor on MR. A case of a pathologically proved subdural disk fragment is presented; MR findings that suggested the correct diagnosis were: proximity of intervertebral disk disease; whorl-like mixed intensity on T2-weighted images; poor visualization of the mass on unenhanced T1-weighted images; and marked ring enhancement following administration of gadolinium.

The handedness of rhesus monkeys. III. Consistency within and across activities.

The results of this study of the hand preferences of rhesus monkeys on three different tasks are threefold: (1) When retested on the same task at intervals exceeding one month virtually all individuals prefer the same hand as they did during the original test, (2) When retested on the same task, the strength of hand preference displayed by each individual is increased. (3) When tested on differing tasks, monkeys display little consistency in the laterality of hand preference or the strength of handedness expressed during different tasks. Many authors have concluded that the lack of obvious intertask consistency in the laterality of hand preference expressed by lower primates constitutes evidence for a corresponding lack of consistent laterality in the cerebral control of this behavior. This has led to them to conclude that cerebral dominance probably does not exist in these animals (Deuel, 1975; Warren, 1977). However, where data is available from the literature, including the present study, all reports show monkeys to more frequently prefer the same hand on all of the unimanual tasks they were given than would be expected by chance alone. This finding suggests that there is a weak tendency for consistent lateralization of hand usage in the monkey. Presumably, there is a corresponding predominance of the cerebral hemisphere contralateral to the preferred hand over its mate. Other studies consistent with the concept of cerebral predominance in the monkey were reviewed. These findings do not constitute evidence for cerebral dominance in the monkey akin to that found in man. They do suggest that when performing certain activities, monkeys may have one hemisphere predominant over the other even though the degree and laterality of predominance may vary greatly from one individual and task to another.

The handedness of rhesus monkeys: II. Concurrent reaching.

Of 171 monkeys tested for handedness, 60 were found to make occasional bilateral concurrent reaches. These reaches accounted for only 1.3% of the total of 600 reaches observed for each animal. Younger animals were observed to make such reaches more frequently than older animals. Concurrent reaching was characterized by a lower degree of preference for the overall preferred hand than unilateral reaches made by the same animals at comparable periods of testing.

Lateralized preferences and right-left discrimination in the monkey: choice of mirror-image shape, position of recovered food and hand usage.

Rhesus monkeys were tested for lateral preferences during mirror-image shape discrimination and food recovery from a row of pellets. Position of recovered food was unrelated to hand preference or mirror-image preference. There was no significant difference in the number of individuals preferring right and left lateral mirror-image shapes. Individuals tended to retain the same mirror-image preference to the same degree upon repeated testing. Animals of greater weight had stronger preferences. In all these respects, the features of mirror-image preference resembled those previously described for hand preference during a simple reaching task. The strength of different lateral preferences expressed by each animal were not significantly related thus failing to support the concept that asymmetric bodily responses can serve as cues for right-left discrimination in the environment. However, when the direction as well as strength of preference was considered, there appeared to be a tendency for animals to prefer the mirror-image shape whose reward bias was opposite to that of the preferred hand. This finding might have been due to a positional bias though there was evidence against this possibility.

Subclavian catheterization for the placement of a ventriculovenous shunt.

Repeated nonfunction of the distal end of a ventriculoperitoneal shunt led to an unsuccessful attempt to introduce the distal catheter into the vena cava through the jugular vein. Subclavian catheterization utilizing a cardiac pacemaker introducer set proved to be a simple and effective means of establishing a ventriculovenous shunt.

A comparison of pressure-volume models in hydrocephalus.

Traditional descriptions of the pressure-volume properties of the craniospinal axis have expressed pressure as a function of volume. This study develops a theoretical and practical rationale for expressing volume as a function of pressure. We tested the rationale by comparing the two functions using pressure and volume data collected from 37 hydrocephalic patients during ventricular fluid removal. Two equivalent expressions were evaluated, one expressing pressure as an exponential function of volume and one relating volume as an exponential function of pressure. Each expression had three parameters, adjustable to the specific case. We used a nonlinear curve-fitting algorithm to determine the best estimate of the parameters. We could fit three-parameter exponential functions of either type to the data in all cases. We found a superior goodness-of-fit to aggregated data when expressing volume as a three-parameter exponential function of pressure changes. This finding is discussed in the context of the preferable number of parameters in a model and the interpretation of the terms in the models. This "reversed" volume-pressure relationship has importance in the development of more complicated models involving these same relationships.

Technical note: the use of nitroglycerin ointment after precarious neurosurgical wound closure.

It is suggested that the application of nitroglycerin ointment to neurosurgical wound closure exhibiting skin pallor or cyanosis can minimize necrosis and dehiscence. Examples of the use of this agent in patients undergoing myelomeningocele closure as well as in a premature infant undergoing ventriculoperitoneal shunting are described.

Clinical clerkships in neurosurgery and neurology at United States medical schools.

The neurology and neurosurgery clinical clerkship experience (excluding lectures and conferences) of the students in U.S. allopathic medical schools during one of the academic years 1986 to 1987 or 1987 to 1988 was surveyed. Almost all schools have at least some students taking these clerkships. The majority of students (78%) have clinical exposure to neurology, but only a minority (28%) take a neurosurgical clerkship; however, far more schools require their students to take neurology clerkships (54%) than neurosurgical clerkships (12%). A few require that either be taken. Overall, 81% of schools require all students to take at least one of these clerkships. For the most part, students taking a clerkship in either specialty do not do so again. The initial and usually unique exposure averages 3.5 weeks in neurology and 2.4 weeks in neurosurgery. For each specialty, required clerkships tended to be shorter than selective clerkships, which in turn were shorter than elective ones. Furthermore, first clerkships offered in the fourth year, whether they were required, selective, or elective, tended to be longer than the corresponding third-year first clerkships at other schools. Whereas the average length of a first clinical clerkship in neurology is almost as long for schools requiring it (3.4 wk) as for those that offer it as an elective or selective (4.0 wk), required neurosurgical clerkships are much shorter (1.5 wk) than elective or selective rotations (3.1 wk). Schools with residency training programs more frequently required students to a clerkship and, consequently, had greater numbers of students taking a clerkship in the corresponding specialty.(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental internuclear ophthalmoplegia.

A midline experimental lesion separating the medial longitudinal fasciculi at and below the level of the abducens nuclei without damaging either fasciculus at the level of the nuclei has produced defects of ocular motility resembling those of clinical internuclear ophthalmoplegia. Electromyographic recordings during lateral gaze demonstrate: (1) lack of inhibition of the lateral rectus muscle in the adducting eye, (2) delayed inhibition of the medial rectus muscle in the abducting eye, and (3) occasional evidence of excitation of the medial rectus muscle of the abducting eye probably associated with pupillary constriction. The presumed physiologic mechanisms involved in conjugate gaze movements are discussed in the light of the experimental findings.

An easily replaceable intracranial catheter. Technical note.

Replacement of a catheter draining an intracranial cyst or a ventricle can be difficult if the fluid space has collapsed. An intracranial catheter which can be safely and accurately exchanged is described. The catheter also offers an advantage during the original placement if the fluid cavity to be drained has a thick wall.

Osteoid osteoma of the cervical spine. Case report.

A case of osteoid osteoma involving the cervical vertebral pedicle is presented which reemphasizes the importance of complete removal of the nidus and the dramatic relief of symptoms following excision.

Reoperation after lumbar intervertebral disc surgery.

This retrospective study includes 53 patients who underwent reoperation after failure of lumbar disc surgery to relieve pain. All patients had leg pain before reoperation, which was successful in 28% of cases. Most clinical features, such as persistence or mode of recurrence of pain, radicular quality of pain, positive straight-leg raising, and myelographic root sleeve defects, were not helpful in predicting successful and unsuccessful reoperations. However, a significantly larger percentage of women than men had successful reoperations. Patients who had past or pending compensation claims, who had sensory loss involving more than one dermatome, or who failed to have myelographic dural sac indentations resembling those caused by a herniated disc did poorly with reoperation. A very convincing myelographic defect appears to be needed to justify reoperation at a previously unoperated location. Excision of scar alone or dorsal rhizotomy was of no avail in these cases.

Diagnosis and treatment of abscess of the central ganglia.

The authors present four cases of abscess of the thalamus and basal ganglia and review an additional 10 cases from the literature. These abscesses appear to be metastatic and are usually associated with a cardiac septal defect or a preceding intrathoracic infection. Fever, elevated white blood count, and/or meningismus, in combination with angiography demonstrating an avascular mass, help distinguish abscess from tumor in this location. The authors advocate aspiration rather than excision.