Rapid Recovery After Hemiplegia with Negative CT Scans
Yes, some patients with hemiplegia can recover rapidly even with negative CT scans, particularly in cases of transient ischemic events, cervical cord neuropraxia, or early ischemic stroke where imaging may initially be negative.
Understanding the Clinical Context
The question addresses a critical diagnostic challenge: hemiplegia with negative neuroimaging. This scenario occurs in several distinct clinical situations that require different management approaches.
When CT Scans May Be Negative Despite Hemiplegia
Ischemic stroke can present with negative initial CT imaging, particularly in the hyperacute phase. 1 In a series of clinically diagnosed ischemic strokes, MRI failed to detect lesions in patients scanned within 24 hours of symptom onset, with strokes localized to cortex, brain stem, and subcortical areas all potentially missed 1. CT is even less sensitive than MRI for acute ischemic changes in the first hours.
Small lacunar infarcts causing pure motor hemiplegia may be subtle or initially invisible on CT. 2 These lesions, typically located in the internal capsule or pons, can produce complete hemiplegia despite being only 1-2 cm in diameter, and early CT scans may not reveal them 2.
Conditions Associated with Rapid Recovery
Transient neurological deficits can mimic stroke with complete resolution. 3 A documented case of cervical cord neuropraxia presented with hemiparesis and sensory abnormalities following trauma, with most symptoms resolving within 24 hours and complete resolution in 5 days, despite negative CT and MRI imaging 3. This represents "cervical cord neuropraxia" which typically resolves within 48 hours 3.
Clinical Decision-Making Algorithm
Immediate Assessment (0-12 Hours)
- Obtain baseline CT immediately to exclude hemorrhage, which would fundamentally change management 4
- Document the exact time of symptom onset as this determines imaging sensitivity and treatment windows
- Assess for trauma history as post-traumatic transient deficits have different implications than spontaneous events 3
- Evaluate anticoagulation status as this affects both hemorrhage risk and repeat imaging protocols 4
Repeat Imaging at 12-24 Hours
For spontaneous intracerebral hemorrhage, repeat CT at 6 and 24 hours after onset is adequate to exclude hematoma expansion in neurologically stable patients. 4 Hematoma expansion occurs in 26% of patients within 1 hour and an additional 12% by 20 hours, but expansion after 24 hours is extremely rare (0%) 4.
For mild traumatic brain injury with negative initial CT, the yield of routine repeat imaging in neurologically stable patients is extremely low. 4 In patients not on anticoagulation with GCS 15 and negative initial CT, delayed intracranial hemorrhage requiring intervention is rare (<1%) 4. A Class I study of 1,292 mild TBI patients with GCS 15 randomized to immediate CT found that none with negative scans developed complications requiring admission or surgery at 3-month follow-up 4.
Special Populations Requiring Extended Monitoring
Anticoagulated patients warrant 24-hour observation even with negative initial CT. 4 In patients on warfarin or NOACs with mild head injury and negative initial CT, delayed ICH occurred in 1.4-4.5% when rescanned at 20-24 hours, though neurosurgical intervention was rarely required 4. However, the single most clinically significant delayed hemorrhage resulting in death occurred in a patient already admitted who experienced early neurological deterioration 4.
Elderly patients on aspirin (≥65 years) may require longer observation. 4 In this population with isolated mild head injury and negative initial CT, 4% developed delayed ICH, with one requiring neurosurgical decompression and another dying 4.
Prognosis for Recovery
Rapid recovery is possible and occurs in specific clinical scenarios:
- Transient ischemic attacks resolve by definition within 24 hours
- Cervical cord neuropraxia typically resolves within 48 hours, though some cases may take up to 6 weeks for complete resolution 3
- Small lacunar infarcts can show variable recovery patterns, though the acute hemiplegia itself indicates completed stroke rather than transient deficit 2
Critical Pitfalls to Avoid
Do not assume negative CT excludes all pathology. 1 MRI is more sensitive for acute ischemic stroke, and even MRI can miss strokes in the hyperacute phase, particularly small brain stem or cortical lesions 1.
Do not discharge anticoagulated patients immediately after a single negative CT. 4 The risk of delayed hemorrhage, while low (1.4-4.5%), includes potential mortality and warrants 24-hour observation with repeat imaging 4.
Do not confuse rapid improvement with benign prognosis in all cases. 3 Even with complete symptom resolution and negative imaging, underlying pathology such as cervical cord injury may have occurred, requiring careful return-to-activity decisions 3.
In neurologically stable mild TBI patients without anticoagulation, routine repeat CT at 12-24 hours is unnecessary and of extremely low yield. 4 The evidence strongly supports that these patients can be safely discharged after a single negative CT with appropriate discharge instructions 4.