Study of the relationship between initial autonomic functions and subsequent motor and sensory recovery, in traumatic cervical spinal cord injury patients

INTRODUCTION: Spinal cord injury (SCI) results in multisystem dysfunction. It is a devastating event which often leads to permanent neurological deficits. Recovery of the SCI quadriplegic patient depends to a large extent on the amount of tract fibres that are intact. Currently the SCI patients are classified based on the extent of preserved motor and sensory functions into American Spinal Injury Association (ASIA) Impairment Scale (AIS) grade A,B,C,D and E (in the order of least to most preserved motor and sensory functions. This classification does not take into account the intactness of the autonomic fibres. Some of the patients show functional improvement by the end of the rehabilitation programme and shift to higher AIS grades. As of now it is not possible to predict accurately which patients will improve. When a cervical SCI patient is admitted for rehabilitation, the clinicians are faced with the dilemma of predicting the recovery in them. The patients themselves and their relatives would like to know the extent to which the patient will recover functionally after rehabilitation. OBJECTIVES: To study whether autonomic pathway integrity assessed through the sympathetic skin response and short-term heart rate variability indices, is useful for prognostication in traumatic cervical spinal cord injury quadriplegic patients. METHODS: Short-term heart rate variability (HRV) indices computed in 24 cervical spinal cord injury AIS grade A/B patients, at the time of admission, were correlated with the change in motor and sensory scores at the end of the rehabilitation programme, using Spearman’s correlation coefficient. Fisher’s exact test was used to study the association between the presence/absence of sympathetic skin response (SSR) at the time of admission and the change in AIS grade at the end of the rehabilitation programme. RESULTS: There was no statistically significant correlation between the HRV indices and the change in motor and sensory scores. Neither was there any statistically significant association between the presence or absence of SSR at the time of admission and the subsequent improvement in AIS grade. The findings of the present study indicate that HRV indices and SSR are not useful parameters to prognosticate recovery in traumatic cervical spinal cord injury quadriplegic patients