Contralateral Sensory Deficits in Left Hemispheric Stroke
In a patient with right upper-motor-neuron facial weakness from a left hemispheric stroke, expect contralateral (right-sided) sensory loss affecting the face, arm, and/or leg, which can range from mild paresthesias to complete hemisensory loss.
Expected Sensory Deficits
The sensory examination should specifically assess for:
- Right-sided paresthesia or sensory loss affecting the face, arm, and/or leg 1
- Tactile deficits (most common form of sensory deficit after stroke) 2
- Proprioception impairment (position sense)
- Pain and temperature sensation loss
- Vibration sense deficits
- Stereognosis (inability to identify objects by touch)
- Graphesthesia (inability to recognize numbers/letters traced on skin)
Severity Assessment
Using the National Institutes of Health Stroke Scale (NIHSS), sensory deficits are scored as 3, 4:
- 0 = No sensory loss
- 1 = Mild sensory loss (patient aware of touch but diminished)
- 2 = Severe sensory loss (patient unaware of touch)
The NIHSS also includes assessment for extinction or inattention (item 11), which evaluates whether the patient neglects or extinguishes stimuli during double simultaneous stimulation in visual, auditory, or sensory modalities 3.
Clinical Patterns
Typical Presentation
Left middle cerebral artery territory strokes commonly produce:
- Right-sided weakness
- Right-sided sensory loss
- Aphasia (if dominant hemisphere)
- Right visual field deficits 1
Important Nuances
Sensory recovery is substantial but variable in the months following stroke, with proprioception showing particularly notable recovery potential 2. However, approximately 21% of stroke patients experience persistent sensory-perceptual deficits 5.
Bilateral sensory symptoms are uncommon but can occur with specific lesion locations. For example, medial medullary lesions affecting the ventral trigeminothalamic tract can produce contralateral facial sensory symptoms, while lateral lesions produce ipsilateral symptoms 6. However, with typical hemispheric strokes, sensory deficits remain strictly contralateral.
Assessment Priorities
Beyond the standard sensory examination, evaluate for:
- Visual field defects (right homonymous hemianopsia affects approximately 30% of stroke survivors) 2
- Neglect syndromes - right-sided neglect with left hemisphere lesions is less common than left-sided neglect with right hemisphere lesions 1
- Sensory ataxia - impaired proprioception can manifest as limb ataxia disproportionate to weakness 3
Common Pitfalls
Do not assume absent sensory complaints mean intact sensation. Patients with aphasia or cognitive impairment may be unable to report sensory symptoms. Formal bedside testing with pinprick, light touch, and proprioception assessment is essential 2.
Sensory deficits are often overlooked despite being significant impediments to optimal motor recovery 7. Impaired sensation directly impacts rehabilitation outcomes and should be systematically assessed and documented.
Central post-stroke pain (CPSP) develops in 2-5% of patients and presents as pain and loss of sensation in the affected limbs, typically from spinothalamic tract damage 5. This can emerge weeks to months after stroke and requires specific pharmacologic management.
The presence and severity of sensory deficits provide important prognostic information and should guide rehabilitation planning, as somatosensory impairment significantly affects motor recovery and functional outcomes 8.