Determining the Functional Status of the Corticospinal Tract Within One Week of Stroke

Summary

This protocol is for evaluating corticospinal tract function within 1 week of stroke. It can be used to select and stratify patients in trials of interventions designed to improve upper limb motor recovery and outcomes and in clinical practice for predicting upper limb functional outcomes 3 months after stroke.

Abstract

High interindividual variability in the recovery of upper limb (UL) function after stroke means it is difficult to predict an individual's potential for recovery based on clinical assessments alone. The functional integrity of the corticospinal tract is an important prognostic biomarker for recovery of UL function, particularly for those with severe initial UL impairment. This article presents a protocol for evaluating corticospinal tract function within 1 week of stroke. This protocol can be used to select and stratify patients in trials of interventions designed to improve UL motor recovery and outcomes after stroke. The protocol also forms part of the PREP2 algorithm, which predicts UL function for individual patients 3 months poststroke. The algorithm sequentially combines a UL strength assessment, age, transcranial magnetic stimulation, and stroke severity, within a few days of the stroke. The benefits of using PREP2 in clinical practice are described elsewhere. This article focuses on the use of a UL strength assessment and transcranial magnetic stimulation to evaluate corticospinal tract function.

Introduction

Upper limb function is commonly impaired after stroke, and recovery of UL function is important for regaining independence in daily living activities¹. Stroke rehabilitation trials are often aimed at improving UL recovery and outcomes after stroke. The majority of stroke rehabilitation research is conducted with patients at the chronic stage (>6 months poststroke), yet most rehabilitation occurs early after stroke^2,3. More research needs to be conducted with patients soon after a stroke to build an evidence base for rehabilitation practice.

One of the gre....

Protocol

All research conducted with human participants must have human ethics approval by the appropriate institutional ethics committee and the study must be conducted in accordance with the declaration of Helsinki.

1. Patient Screening

1. Screen all patients for PREP2 suitability within 72 h of stroke onset.
   NOTE: Patients are suitable if they have had a unilateral ischemic or hemorrhagic stroke within the last 72 h, have new UL weakness, and are 18 years or older.

Discussion

CST function evaluated with MEP status is a key prognostic biomarker for UL recovery and outcome after stroke. A total of 95% of patients with a functional CST at 1 week poststroke achieve an Action Research Arm Test (ARAT) score of at least 34 out of 57 by 3 months poststroke¹⁷. Conversely, 100% of patients without a functional CST at 1 week poststroke achieve an ARAT score of less than 34 by 3 months poststroke¹⁷. Evaluating CST function within a week poststroke may impro.......

Materials

Name	Company	Catalog Number	Comments
alcohol/skin cleansing wipes	Reynard		alcohol prep pads
electromyography electrodes	3M		red dot electrodes
Magstim TMS coil	Magstim		flat figure-8 coil
razors	any
skin prep tape	3M		red dot skin prep tape
TMS stimulator	Magstim		Magstim 200 single pulse stimulator