Faculty Bibliography

This case report details the complex rehabilitation of an adolescent patient with congenital heart disease with anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) who presented with a sudden cardiac arrest. The International Classification of Functioning, Disability and Health for Children and Youth, World Health Organization (ICF-CY WHO) principles were used to guide the course of the patient's acute inpatient rehabilitation.

The coronavirus (COVID-19) pandemic triggered wide scale implementation of telemedicine in the United States. The government response, Coronavirus Aid, Relief, and Economic Security (CARES) Act, permitted loosening of existing restrictions on telemedicine enabling its rapid incorporation into the delivery of medical care for children and adults. Prior to COVID-19, few pediatric physiatrists had opportunities to access high fidelity telemedicine platforms to provide health care for patients with special needs, mobility impairments, developmental delays, neuromuscular disorders or other complex medical conditions. This literature review will explore how telemedicine can optimize health care delivery options for pediatric physiatrists in various inpatient and outpatient settings such as consultations, acute inpatient units, outpatient clinics and long-term care facilities. Detailed analysis of the current research in telemedicine applications as well as a critical review of the limitations and barriers for its use offers a plethora of opportunities for enhancement of continuity and coordination of care. Telemedicine may decrease healthcare disparities and increase access of care for children with special needs. Additional research is needed to assess the efficacy of telemedicine when addressing complex medical conditions in children.

Case Description: The patient presented with ascending numbness and difficulty walking for 3 weeks. He denied any recent travel history or illness. He reported daily nitrous oxide inhalation via 'whippets' for the past 6 months. Neurological examination revealed reduced vibration and proprioception in bilateral lower extremities, an ataxic gait and bilateral foot drop. The remainder of the examination was normal.
Setting(s): Acute inpatient rehabilitation Patient: 17-year-old patient with numbness in bilateral feet for 3 weeks. Assessment/Results: Laboratory workup revealed an elevated methylmalonic acid level consistent with Vitamin B12 deficiency. EMG revealed moderate acute motor axonal polyneuropathy. An MRI of the spinal cord was refused by the patient. He was treated with intramuscular vitamin B12 replacement, followed by oral vitamin B12 for 3-6 months. He was admitted to acute inpatient rehabilitation where he received multidisciplinary treatment from physical therapy, occupational therapy, cognitive rehabilitation and psychological support. Patient was advised to discontinue nitrous oxide use and referred to an addiction counseling center. Upon discharge, patient ambulated with modified independence and bilateral ankle-foot orthoses due to foot drop.
Discussion(s): Nitrous oxide is an increasingly popular recreational drug used amongst young adults. The typical mode of inhalation involves small pressurized canisters of nitrous oxide in whipped cream dispensers. Nitrous oxide irreversibly inactivates vitamin B12, eventually leading to deficiency. Vitamin B12 depletion causes demyelination and gliosis within the dorsal cord of the spinal cord and peripheral nerves. In addition, cognitive impairment and optic atrophy may occur. The common neurological presentation of toxicity includes paresthesias and gait disturbance, which improve over time with high dose vitamin B12 replacement.
Conclusion(s): Nitrous oxide-induced vitamin B12 deficiency leading to neuropathy is a rare diagnosis seen in the acute rehabilitation setting that physiatrists should be able to recognize. Children and adults with neurological symptoms should have a thorough illicit drug history screen during history taking

Case Description: Nine-year-old female with Down syndrome presented with progressive functional deficits and was found to have atlantoaxial subluxation with severe cord compression and myelopathy.
Setting(s): Acute inpatient rehabilitation Patient: Nine-year-old female with Down syndrome presented with left sided weakness, sensory deficits, and difficulty walking for 3 months. Assessment/Results: Brain MRI revealed marked atlantoaxial subluxation with compression of the cord at the level of the odontoid process. She underwent bilateral sub-occipital craniectomy, C1 laminectomy and occipital-C4 fusion. She was admitted to acute inpatient rehabilitation to address her continued functional deficits.
Discussion(s): Atlantoaxial instability (AAI) refers to increased mobility of the axis on the atlas. It is more common in those with Down syndrome, affecting 10-20%. On lateral neck radiographs, a large anterior atlantoodontoid distance can indicate instability and in 1-2%, the displaced odontoid can compress the cord causing weakness, abnormal gait, or death. Recently updated guidelines from the American Academy of Pediatrics (AAP) no longer recommend screening radiographs for children with Down syndrome. The American Academy of PM&R continues to recommend radiographs for asymptomatic children at age three to five or prior to participation in contact sports. As specialists in musculoskeletal medicine and as advocates for inclusion and an active lifestyle, pediatric physiatrists should be aware of and appropriately screen for this pathology. As per AAP, plain radiographs do not adequately identify at-risk children. Indeed, a study reviewing adults with Down syndrome found a low correlation between radiological findings and symptoms of AAI. Conversely, two studies in children with Down syndrome evaluated enhanced neuroimaging techniques, one being the use of novel radiographical measurements and the second being the use of a dynamic MRI, the latter better distinguishing patients at risk for neurologic injury.
Conclusion(s): An interdisciplinary, evidence-based consensus regarding screening guidelines for atlantoaxial subluxation is needed to avoid potentially devastating neurological consequences of atlantoaxial subluxation

The present study provides an experimental model of the apoptotic death of pyramidal neurons in rat olfactory cortex after total bulbectomy. Terminal transferase (TdT)-mediated deoxyuridine triphosphate (d-UTP)-biotin nick end labeling (TUNEL), DNA electrophoresis, and neuronal ultrastructure were used to provide evidence of apoptosis; neurons in olfactory cortex were counted by stereology. Maximal TUNEL staining occurred in the piriform cortex between 18 and 26 hr postbulbectomy. Within the survival times used in the present study (up to 48 hr postlesion), cell death was observed exclusively in the piriform cortex; there was no evidence of cell death in any other areas connected with the olfactory bulb. Neurons undergoing apoptosis were pyramidal cells receiving inputs from, but not projecting to, the olfactory bulb. The apical dendrites of these neurons were contacted by large numbers of degenerating axonal terminals. Gel electrophoresis of DNA purified from lesioned olfactory cortex showed a ladder pattern of fragmentation. Inflammatory cells or phagocytes were absent in the environment of degenerating neurons in the early stages of the apoptotic process. The present model suggests that deafferentation injury in sensory systems can cause apoptosis. In addition, olfactory bulbectomy can be used for investigating molecular mechanisms that underlie apoptosis in mature mammalian cortical neurons and for evaluating strategies to prevent the degeneration of cortical neurons.

Nerve growth factor (NGF), which has long been considered to be a trophic factor for peripheral sensory and sympathetic neurons, has been found recently to influence cholinergic neurons in the basal forebrain and neostriatum. In the present study, we provide evidence that brainstem neurons in the perihypoglossal area that relay information from the inner ear and vestibular apparatus to the cerebellum and tectum are responsive to NGF. These neurons, which are located in the nucleus prepositus hypoglossi (NPH), spinal vestibular nucleus, cochlear complex, and gigantocellular and paragigantocellular nuclei of the reticular formation, express functional receptors for NGF and up-regulate the expression of trkA receptors after injection of NGF into targets. In addition, the developmental up-regulation of NGF in the cerebellum coincides with the differentiation of the perihypoglossal nuclei. These results suggest that neurons representing the principal brain relays for auditory and vestibular pathways and perihypoglossal neurons involved in gaze coordination are a novel group of central neurons (besides cholinergic neurons in the basal forebrain and neostriatum) that respond to NGF.

We examined the degeneration of neocortical neurons in normal aging and Alzheimer's disease (AD) using terminal transferase (TdT)-mediated deoxyuridine triphosphate (d-UTP)-biotin nick-end labeling (TUNEL), a method that identifies DNA strand breaks and constitutes a positive marker for dying neurons. TUNEL was positive in neurons, glia, and microglial cells in AD but not in younger or age-matched cognitively characterized controls. Neuronal labeling in AD was most conspicuous in cortical layer III in the early stages of the disease and became more widespread as the disease progressed. In addition, we observed TUNEL of lamina III neurons in a subset of older subjects who had normal cognition but abundant neocortical senile plaques. In concert, the availability of a direct marker of dying neurons allows for specific correlations of cell death with other neuropathological markers as well as clinical variables. Observations from the present study suggest that the death of cortical neurons precedes the symptomatic stage of AD and evolves in parallel with the clinical progression of the disease and that there appears to be an association between the degree of cell death and the severity of senile plaques.

Neurons in the nucleus basalis of Meynert (NBM) were analyzed morphometrically in 21 rhesus monkeys ranging in age from 9 to 33 years. Numbers of cholinergic neurons were similar across all ages at several NBM levels in either Nissl-stained paraffin sections or sections processed immunocytochemically for nerve growth factor receptor (p75LNGFr). Size of NBM neurons was larger in aged monkeys than young monkeys at all NBM levels, particularly in the most posterior subdivision. A subset of monkeys were behaviorally characterized shortly before death, and partial correlation analyses indicated that increased age was associated with declines in recognition memory, visuospatial orientation, and reaction time. Controlling for age, spatial memory and concurrent discrimination abilities were associated with lower cell number in intermediate NBM. Numbers of neurons in anterior NBM did not correlate with any behavioral measure. These observations indicate that numbers of NBM cholinergic neurons are stable with age, that NBM neurons become hypertrophic in older animals, and that morphometric indices of cholinergic neurons are associated with cognitive function.