Pattern of startle reflex to somatosensory stimuli changes after spinal cord injury

The Journal of Spinal Cord Medicine, 2018 · DOI: 10.1080/10790268.2016.1211580 · Published: January 1, 2018

Simple Explanation

Spinal cord injury (SCI) can alter how our nervous system responds to unexpected stimuli. This study looks at two types of reflexes: the auditory startle response (ASR) to sounds and the startle reflex to somatosensory stimuli (SSS) to touch or electrical stimulation. The researchers found that after SCI, the ASR was stronger, meaning people with SCI reacted more intensely to sudden sounds. However, the SSS, particularly the blink reflex (SBR) involving eye muscles, was weaker in those with SCI. These changes suggest that SCI leads to a reorganization of the nervous system. The heightened ASR could be a compensatory mechanism, while the reduced SSS might be related to changes in how the brain processes sensory information after SCI.

Study Duration

8 months to 15 years post-SCI

Participants

14 patients with SCI and 18 age-matched healthy volunteers

Evidence Level

Not specified

Key Findings

1
Patients with SCI exhibited exaggerated auditory startle responses (ASRs) compared to healthy controls.
2
The probability of the somatosensory evoked blink reflex (SBR), a component of SSS, was lower in patients with SCI compared to healthy subjects.
3
There were no significant differences in other SSS responses (SCM and BB muscles) between the SCI and control groups.

Research Summary

This study investigated the impact of spinal cord injury (SCI) on auditory startle responses (ASR) and startle reflexes to somatosensory stimuli (SSS). The findings revealed that ASRs were enhanced in patients with SCI, while the somatosensory evoked blink reflex (SBR) was hypoactive. Other SSS responses were not significantly different between the groups. The study suggests that SCI leads to changes in the excitability and processing of sensory information in the nervous system, potentially due to reorganization and compensatory mechanisms.

Practical Implications

Rehabilitation Strategies

Understanding changes in startle reflexes may inform rehabilitation strategies for SCI patients.

Sensory Modulation

Impaired control of eye closure and loss of sensory modulation of the blink reflex may suggest the need for special eye care for SCI patients.

Peripersonal Space

Changes in peripersonal space after SCI may affect the rehabilitation process.

Study Limitations

1
The study did not use area-under-the-curve to analyze excitability, relying on amplitude and duration measurements.
2
The sample size of 14 patients with SCI may limit the generalizability of the findings.
3
The study design does not allow for conclusions about the causal mechanisms underlying the observed changes in startle reflexes.

Your Feedback

Was this summary helpful?

Back to Spinal Cord Injury