Electrodiagnosis in spinal cord injured persons with new weakness or sensory loss: central and peripheral etiologies

Radial palsy in an individual with high-level chronic spinal cord injury

INTRODUCTION

Prolonged compression is a common cause of radial neuropathy in able-bodied individuals but has not been reported in individuals with chronic SCI. This is despite the fact that individuals with SCI may be at increased risk of peripheral nerve injuries due to wheelchair mobility and baseline sensory deficits. Furthermore, diagnosis of peripheral nerve injury poses a unique challenge in this population because symptoms and signs are superimposed on pre-existing central deficits.

CASE PRESENTATION

We present the case of a 48-year-old man with a C6 AIS A SCI from a motor vehicle accident 22 years earlier who had a new onset compressive radial neuropathy. At initial assessment he complained of paresthesia along his lateral right arm accompanied by new onset wrist-drop. Subsequent radial nerve conduction studies revealed severe reductions in amplitude for sensory and motor action potentials. The patient was managed with mobility exercises and vitamin B supplementation and showed full recovery of motor and sensory function to baseline levels on follow-up 4 months after the injury.

DISCUSSION

The electrophysiologic profile of this patient is illustrative of severe nerve compression for an extended time period. Unlike able-bodied individuals who can reposition themselves to alleviate nerve compression, individuals with SCI may be unaware of nerve compression or unable to reposition themselves. This highlights the need for precautionary measures such as maneuvers and devices to provide trunk and limb stability along with the use of medical alert devices that allow individuals to access timely help when unattended.

Focal and Generalized Peripheral Nerve Dysfunction in Spinal Cord???Injured Patients

SUMMARY

The present study was undertaken to quantitate the incidence and clinical patterns of peripheral nerve dysfunction distal to the level of injury in patients with spinal cord injury (SCI). Through retrospective analysis, SCI patients were identified after referral for neurophysiologic investigation of new neuropathic symptoms. In total, peripheral nerve or nerve root lesions developed in 34 SCI patients, most commonly within the first year after SCI. Carpal tunnel syndrome was the most common upper-limb neuropathy (34%); sciatic neuropathy was the most common lower-limb abnormality (8.5%). A significant proportion of SCI patients had neurophysiological evidence of generalized peripheral nerve dysfunction, specifically axonal neuropathy (18%). Tetraplegic patients developed more frequent peripheral nerve lesions than paraplegics. Although most SCI patients presented within 4 years of their original injury, in a more chronic population of SCI patients that developed neuropathy 5 years after injury, 60% had evidence of coexistent syrinx formation. Maintenance of peripheral nerve function is a critical issue in all acute SCI and rehabilitation units, particularly in the context of spinal cord neuronal regeneration projects.

Aging with spinal cord injury

The years after SCI may be associated with acceleration of the aging process because of diminished physiologic reserves and increased demands on functioning body systems. Clinicians with expertise in the treatment and prevention of SCI-specific secondary complications need to collaborate with gerontologists and primary care specialists and need to invest in the training of future physicians to ensure a continuum of accessible, cost-effective, and high-quality care that meets the changing needs of the SCI population. Managed care payers often do not adequately cover long-term disability needs to prevent secondary SCI-specific complications. In this era of increasing accountability, evidence-based clinical practice guidelines are needed to document scientific evidence and professional consensus to effectively diagnose, treat, and manage clinical conditions; to reduce unnecessary testing and procedures; and to improve patient outcomes. Longitudinal research is needed to minimize cohort effects that contribute to misinterpretation of cross-sectional findings as representative of long-term changes in health and functioning. However, longitudinal studies confound chronologic age, time since injury, and environmental change. Thus, time-sequential research, which controls for such confounding effects, is essential, as is research on the effects of gender,culture, and ethnicity. If we consider how much progress has been made over the past 50 years with respect to SCI mortality related to infectious disease, we can expect to achieve even greater progress against the effects of aging in the next 50 years. Recent developments in molecular biology regarding growth and neuro-trophic factors are bringing us closer to the goal of repairing the damaged spinal cord. The challenge remains for rehabilitation professionals to provide the most comprehensive and holistic approach to long-term follow-up, with an emphasis on health promotion and disease prevention, to postpone functional decline and enhance QOL.

Myotonic dystrophy presenting as new-onset hand weakness and recurrent pneumonia in a patient with paraplegia: A case reportaaNo commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors(s) or upon any organization with which the author(s) is/are associated

We describe a previously independent T11 paraplegic patient who had delayed-onset hand weakness and recurrent pneumonia caused by myotonic dystrophy. A man in his late thirties suffered a thoracic spinal cord injury (SCI) from a gunshot wound at the age of 17 years, with resultant T11 American Spinal Injury Association class A paraplegia. He lived independently until the age of 36 years when he was hospitalized multiple times for pneumonia. During a rehabilitation stay after one of the acute hospitalizations, the patient's hand weakness and diffuse muscular atrophy were noted. Electrodiagnostic testing was performed, which showed myotonic discharges. Genetic testing was consistent with myotonic dystrophy. This case shows the importance of considering causes of weakness that affect the population as a whole when evaluating a patient with SCI who presents with delayed-onset weakness.

EMG for assessing the recovery of voluntary movement after acute spinal cord injury in man

OBJECTIVE

Multi-channel electromyogram (EMG) was used to examine the pattern and time-course of voluntary contraction recovery in subjects with acute traumatic spinal cord injury (SCI), concentrating on the latest time after injury at which a given muscle would begin to show voluntary recruitment.

METHODS

We conducted repeated measures of voluntary contractions of 12 lower limb muscles (for all subjects) and 12 upper-limb muscles (for subjects with cervical injury), beginning within days of the injury and extending for 1 or more years post-injury. The EMG interference pattern was scored in a blinded fashion from tape records.

RESULTS

We recruited 229 subjects, including 152 from whom repeated measures were made. Several different patterns of recovery were identified. For persons with motor-incomplete injury to the cervical or thoracic spine, EMG recruitment had not yet occurred by 5 weeks post-injury in roughly 1/2 of all lower limb muscles, and prolonged delays between injury and recruitment onset were sometimes seen. Injury to the thoracolumbar spine was frequently associated with very long delays (i.e. >1 year) between injury and resumption of volitional contraction of distal lower limb muscles.

DISCUSSION

The incidence of neurologically incomplete SCI is rising. In such subjects, delays of 1 or more months between injury and the onset of voluntary contraction are common for muscles of the distal upper limbs (for cervical injury) and lower limbs. Given the abbreviated period of in-patient rehabilitation now routine in the United States, these subjects in particular will benefit from frequent follow-up evaluations to assess spontaneous recovery and design appropriate rehabilitation strategies to maximize functional independence. Moreover, the potential for delayed recovery must be considered when designing and implementing novel clinical interventions for treating SCI, to better differentiate between spontaneous and treatment-related improvements in neurologic function.

Functional changes in persons aging with spinal cord injury

Declines in general physical function and the effect of these changes on activities of daily living and needs for assistance were assessed in 150 individuals with spinal cord injury (SCI). The sample consisted of outpatients returning for follow-up at the spinal cord injury clinic at Rancho Los Amigos National Rehabilitation Center in Downey, CA. The average duration of injury of the sample was 13 years (range 1-37), and average age was 38 years (range 18-64). Twenty-four percent of those sampled experienced a decline or change in their physical function within the last 5 years. Individuals experiencing declines were significantly older than those without changes, averaging 45 years versus 36 years. The group with change also had a longer duration of injury, averaging 18 years versus 11 years compared to the group reporting no declines. Fatigue was the most frequently reported problem, followed by pain and weakness. Over half of the group with changes required additional assistance with activities of daily living (ADLs). Family members were the primary helpers for both ADLs and instrumental activities of daily living (IADLs) for those persons experiencing changes. The use of assistive technology, primarily equipment for bathing, toileting, and low technology devices, increased with time. The increased vulnerability to loss of function in persons with advancing age and duration of injury in this population with SCI suggests the need for early preventative measures, routine assessments to detect changes, and access to health care and supportive services to alleviate or minimize the effect of these changes.