Pure Sensory Stroke as an Isolated Manifestation of the Lateral Medullary Infarction

Pure sensory stroke is a common manifestation of a thalamic stroke and may occur less frequently in the infarction of the brainstem, internal capsule, and parietal cortex. The authors report a 47-year-old man who presented with loss of pain and temperature sensation in the left face, arm, trunk, and leg and was found to have a right lateral medullary infarction on diffusion-weighted magnetic resonance imaging. To the authors' knowledge, this is the first case describing pure sensory stroke as a single, isolated manifestation of the lateral medullary infarction that was detected by diffusion-weighted magnetic resonance imaging. This case suggests that with the availability of diffusion-weighted magnetic resonance imaging, pure sensory stroke may carry a broader spectrum of the anatomical localizations than previously determined and can localize to the lateral medulla. Therefore, a possibility of medullary infarction should be considered when a patient presents with pure sensory stroke, especially when diffusion-weighted magnetic resonance imaging is not immediately available to provide radiographic correlation.     

Brachiofacial pure motor stroke.

Pure motor stroke is the commonest lacunar syndrome, but it may be associated with nonlacunar mechanisms of infarction. Pure motor brachiofacial weakness has been considered as a partial syndrome depending on a lacunar mechanism. We studied the correlations between stroke type, topography of infarction and etiology in 22 patients with pure motor brachiofacial weakness who were consecutively admitted to our stroke unit during a 10-year period. Seventeen patients had a small deep infarct, 4 had a cortical infarct in the superficial MCA territory and 1 had no specific lesion. The part of the cardiovascular risk factors was about 36% for smoking, 13% for diabetes mellitus, 60% for dyslipidemia and 40% for heart disease. Hypertension was present in 75% of our cases. None of the patients had a large artery stenosis on Doppler ultrasonography. We concluded that brachiofacial pure motor stroke is not always correlated to lacunar infarcts and may be due to a cortical infarct. MRI should be performed when brain CT is normal because of the implications it may have in management and therapy.     

Diffusion-weighted MRI diagnosis of pure motor stroke limited to primarily distal leg weakness.

Pure motor stroke (PMS) manifesting as distal weakness of a single extremity has rarely been described. The authors report a 59-year-old man with PMS who had primarily distal weakness of a single lower extremity, which to the authors' knowledge has not been previously described. Four days after onset, positive diffusion-weighted imaging confirmed that the small subcortical T2-weighted hyper-enhancing and nonenhancing T1-weighted hypo-intensity noted on magnetic resonance imaging (MRI) represented an acute PMS that was the cause of the patient's weakness. Increased awareness of this rare clinical presentation of PMS coupled with the promise of imaging the PMS with diffusion-weighted MRI should lead to earlier stroke intervention in these patients.     

Pure motor stroke: a reappraisal.

We studied the correlations between the pattern of weakness, stroke type, topography, and etiology in 255 patients whose first stroke was manifested by isolated hemiparesis. They represented 14% of consecutively admitted stroke patients. The weakness distributions were as follows: face, upper limb, and lower limb (FUL) (50%); face and upper limb (FU) (29%); upper limb (U) (10%); and upper and lower limb (UL) (9%). Twenty-nine percent of the patients had dysarthria, which was of no localizing value. Less than one half of the patients had a deep infarct, and one third had a potential embolic source from the heart or large arteries. Logistic regression analysis showed that history of hypertension and type of weakness distribution were the main factors accounting for lesion localization: patients with FUL distribution and hypertension had a 90% probability of deep infarct; patients either with FUL distribution but no hypertension or with UL distribution and hypertension each had 70% probability of deep infarct. Pure motor monoparesis was almost never caused by a deep infarct. We suggest that the assumption of a lacunar etiology to a pure motor stroke should be applied only to patients with FUL involvement.     

Clinical study of 222 patients with pure motor stroke

The objective was to assess the frequency of pure motor stroke caused by different stroke subtypes and to compare demographic, clinical, neuroimaging, and outcome data of pure motor stroke with those of patients with other lacunar stroke as well as with those of patients with non-lacunar stroke. Data from 2000 patients with acute stroke (n=1761) or transient ischaemic attack (n=239) admitted consecutively to the department of neurology of an acute care 350 bed teaching hospital were prospectively collected in the Sagrat Cor Hospital of Barcelona stroke registry over a 10 year period. For the purpose of the study 222 (12.7%) patients with pure motor stroke were selected. The other study groups included 218 (12.3%) patients with other lacunar strokes and 1321 (75%) patients with non-lacunar stroke. In relation to stroke subtype, lacunar infarcts were found in 189 (85%) patients, whereas ischaemic lacunar syndromes not due to lacunar infarcts occurred in 23 (10.4%) patients (atherothrombotic stroke in 12, cardioembolic stroke in seven, infarction of undetermined origin in three, and infarction of unusual aetiology in one) and haemorrhagic lacunar syndromes in 10 (4.5%). Patients with pure motor stroke showed a better outcome than patients with non-lacunar stroke with a significantly lower number of complications and in hospital mortality rate, shorter duration of hospital stay, and a higher number of symptom free patients at hospital discharge. After multivariate analysis, hypertension, diabetes, obesity, hyperlipidaemia, non-sudden stroke onset, internal capsule involvement, and pons topography seemed to be independent factors of pure motor stroke in patients with acute stroke. In conclusion, about one of every 10 patients with acute stroke had a pure motor stroke. Pure motor stroke was caused by a lacunar infarct in 85% of patients and by other stroke subtypes in 15%. Several clinical features are more frequent in patients with pure motor stroke than in patients with non-lacunar stroke.     

An unusual presentation of hypokalemic paralysis with evolving pure motor hemiparesis

Pure motor hemiparesis is a vascular syndrome that is occasionally mimicked by central or spinal pathologies. However, metabolic neuromuscular disorders have not been reported to mimic this condition. We present a 52-year-old male patient with hypokalemic paralysis who presented with the early symptoms of acute-onset pure motor hemiparesis. Neurological examinations revealed right-sided weakness without bulbar, extraocular, or respiratory involvement. Ischemic stroke was initially diagnosed on the basis of the acute-onset unilateral motor deficit and the patient’s history of hypertension, stroke, and previous cerebral infarctions. The right hemiparesis and weakness of the left limbs worsened on the day after admission. The patient’s weakness rapidly reversed after correction of hypokalemia, and a diagnosis of hypokalemic paralysis was finally established. This unusual hemineurological presentation should alert medical personnel to the possibility of reversible metabolic neuromuscular disorders, thereby avoiding delayed diagnosis.     

Diagnosis and neuroimaging of acute stroke producing distal arm monoparesis

Strokes which result in the isolated, pure motor weakness of an upper extremity are unusual and under-recognized cerebrovascular syndromes. Few reports in the literature describe the syndrome adequately or provide substantive clinical or anatomical correlation. Moreover, it may be misdiagnosed as a disorder of the peripheral nervous system because of the lack of pyramidal tract signs or the involvement of speech, the face, or lower limbs. We describe 35 patients who presented with sudden isolated pure motor weakness of an arm or hand caused by stroke, and provide clinical anatomic correlation of the lesion, stroke etiology, and outcome. Between December 1997 and November 2002, we prospectively identified 35 cases of distal arm monoparesis (DAMP) from among 4818 acute stroke and stroke related admissions to the Lehigh Valley Hospital. We included all patients with isolated weakness of one arm or hand unassociated with objective sensory, coordination, or language deficit, and no significant involvement of speech, the ipsilateral face, or leg. We examined clinical features, neuroimaging, etiology of stroke, and the prognosis of patients with the syndrome over a mean follow-up of 1.7 years. DAMP is an unusual form of cortical infarct which occurs in the parietal lobe or central sulcus region, comprising less than 1% of stroke cases. The infarcts are not caused by classical deep white matter lacunar infarctions, and are clearly delineated as superficial small cortical infarcts by magnetic resonance imaging (MRI)/diffusion-weighted imaging (DWI). Although the prognosis for recovery is uniformly good, the recurrent stroke risk was 14% over 1.7 year mean follow-up.     

Diffusion-weighted MRI in acute lacunar syndromes. A clinical-radiological correlation study.

BACKGROUND AND PURPOSE: Clinical-radiological correlation studies in lacunar syndromes have been handicapped by the low sensitivity of CT and standard MRI for acute small-vessel infarction and their difficulty in differentiating between acute and chronic lesions. METHODS: We prospectively studied 43 patients presenting with a classic lacunar syndrome using diffusion-weighted MRI, a technique with a high sensitivity and specificity for acute small-vessel infarction. RESULTS: All patients were scanned within 6 days of stroke onset. An acute infarction was identified in all patients. Pure motor stroke was associated with lesions in the posterior limb of the internal capsule (PLIC), pons, corona radiata, and medial medulla; ataxic hemipareses with lesions in the PLIC, corona radiata, pons, and insular cortex; sensorimotor stroke with lesions in the PLIC and lateral medulla; dysarthria-clumsy hand syndrome with lesions in the PLIC and caudate nucleus; and pure sensory stroke with a lesion in the thalamus. Supratentorial lesions extended into neighboring anatomic structures in 48% of the patients. CONCLUSIONS: Lacunar syndromes can be caused by lesions in a variety of locations, and specific locations can cause a variety of lacunar syndromes. Extension of lesions into neighboring structures in patients with lacunar syndromes appears to be more frequent than previously described in studies using CT and standard MRI.     

Brachial monoparesis as an isolated manifestation of a paramedian pontine ischemic lesion

Pure monoparesis is a rare condition characterized by weakness limited to one limb without any other neurologic deficits. We herein report an extremely infrequent case of pure motor monoparesis not due to cortical infarctions but due to a paramedian pontine infarction. A 41-year-old woman was admitted with a sudden onset of weakness in her right upper extremity. On neurological examination, there were no abnormalities except for monoparesis (motor grade IV/V) in the right upper extremity. A magnetic resonance imaging of the brain showed an acute small ischemic lesion in the left paramedian pontine area.     

A case of pure motor monoparesis due to pontine infarction

Pure motor hemiplegia (PMH) is a common manifestation of lacunar infarction. However, pure motor monoparesis (PMM), isolated corticospinal tract deficits confined to one limb, have received little attention. We observed a patients in whom the clinical feature was compatible with PMM and discussed the possible pathomechanism of PMM.     

Pure motor stroke as the most frequent lacunar syndrome: A clinical update

Pure motor stroke (PMS), also known as pure motor hemiparesis, is the most common of any lacunar form (between one half and two thirds of cases, depending on the series). In an acute stroke registry, 733 patients presented a lacunar infarct and PMS accounted for 12.7% (n = 342) of all first-ever stroke patients and for 48% of all lacunar syndromes. The posterior limb of the internal capsule, corona radiata, and pons are the most frequent brain topographies. Infarcts in the mesencephalus or medullary pyramid have been exceptionally reported. This present update is focused on the clinical evidence and mechanisms underlying the relationship between PMS and different stroke etiologies.     

Clinical lacunar syndromes as predictors of lacunar infarcts. A comparison of acute clinical lacunar syndromes and findings on diffusion-weighted MRI

OBJECTIVES: To evaluate if patients with acute lacunar syndromes have acute lacunar infarcts or other types of cerebral lesions on diffusion-weighted MRI. METHODS: Patients with acute lacunar syndromes underwent echo-planar diffusion MRI of the brain within 3 days after stroke onset. Localization and size of lesions with hyperintense signal were determined, compared with clinical characteristics and with findings on follow-up T2-weighted MRI. RESULTS: Twenty-three patients participated in the study. Thirteen patients had pure motor stroke, 1 pure sensory stroke, 8 sensorimotor stroke, and 1 ataxic hemiparesis. Twenty-two patients had at least one lesion with increased signal on diffusion-weighted MR images. These acute lesions were in the internal capsule/ basal ganglia/thalamus in 13 patients, subcortical white matter in 5 patients, brainstem in 2 patients, cortex (multiple small lesions) in 1 patient, and cortex + basal ganglia in 1 patient. The median volume of the lesions was 0.6 ml on the initial examination and on follow-up, of 17 patients after 1 to 5 months, 0.5 ml. CONCLUSIONS: Almost all patients with acute ischemic lacunar syndromes have acute lesions on echo-planar diffusion-weighted MRI within 3 days after stroke onset. These lesions are mostly small and subcortical, compatible with lacunar infarcts caused by single penetrating artery occlusion, but in a minor proportion of patients (2 of 23 in our study) a cortical involvement is found.     

Acute isolated capsular stroke. A clinical study of 148 cases

The objectives of the study were to assess differential features between capsular stroke of ischemic and hemorrhagic origin, and to compare capsular strokes with all other (non-capsular) strokes. Data of 148 patients with isolated capsular stroke were collected from a prospective hospital-based stroke registry in which 2000 consecutive acute stroke patients were included. Isolated capsular stroke accounted for 8.4% of strokes included in the registry (8.4% of ischemic strokes and 10.5% of intracerebral hemorrhages). Capsular stroke of hemorrhagic origin (n = 24) was more severe than ischemic capsular stroke (n = 124) as determined by a significantly higher in-hospital mortality, length of stay, and lower number of patients free of functional deficit at discharge. After multivariate analysis, limb weakness, sudden onset, and sensory symptoms were independently associated with capsular hemorrhage, whereas pure motor hemiparesis appeared to be associated with capsular infarction. In summary, one of each 12 patients with acute ischemic stroke and one of each 10 patients with acute intracerebral hemorrhage had an isolated capsular stroke. Lacunar syndrome was the most frequent clinical presentation being more common (particularly pure motor hemiparesis) in ischemic than in hemorrhagic capsular stroke. Capsular hemorrhage and capsular infarction showed identical risk factor profiles suggesting the same underlying vascular pathology for both conditions.     

Variation in prophylactic anticoagulation for venous thromboembolism among acute stroke patients

Asians were known to have relatively lower incidence of deep vein thrombosis (DVT) compared with Caucasians. We aimed to evaluate rates of prophylactic anticoagulation among Korean acute stroke patients who are at high-risk for developing DVT. Of 1295 patients with acute ischemic stroke who were at high-risk for developing DVT, anticoagulation was used in only 21 patients (1.6%; 95% Confidence Interval, 0.9–2.3) during admission. The use of anticoagulation did not differ in relation to age, stroke severity, leg motor weakness, or functional outcomes at discharge. Prophylactic anticoagulation was rarely used in Korean stroke patients who were at high-risk for developing DVT.     

Brain tumor presenting as an acute pure motor hemiparesis

Acute pure motor hemiparesis is a clinical syndrome of isolated hemiparesis usually related to lacunar infarction, although other etiologies have been described. We recently encountered three patients with the abrupt onset of pure motor hemiparesis as the initial manifestation of primary or metastatic brain tumor. In each patient, early computed tomography demonstrated a nonhemorrhagic, right frontal, enhancing mass lesion. While the mechanism whereby brain tumor may present abruptly and simulate a stroke remains uncertain, these cases illustrate that pure motor hemiparesis can be the initial symptom of intracranial tumor. Early computed tomography or magnetic resonance imaging is suggested for all patients who present acutely with pure motor hemiparesis.     

The classic lacunar syndromes: clinical and neuroimaging correlates

Background:  Although lacunar syndromes (LSs) are aimed to be linked to lacunar infarcts, the relation between both is still not very well defined.
Purpose:  The present retrospective study tries to define more specifically the clinical and the neuroimaging characteristics of the five most classic LSs.
Patients and methods:  Out of a series of 1617 consecutive stroke patients, admitted to the Ghent University Hospital, 293 presented a classic LS. Magnetic resonance imaging (MRI) with diffusion-weighted imaging (DWI) was performed within 5 days after stroke onset in 227 patients. An acute territorial infarct was demonstrated in 54 patients. The study population finally consisted of 173 patients with a classic LS in whom the responsible lacune was demonstrated or in the absence of another type of infarct.
Results:  The responsible lacune was demonstrated with DWI in 104 patients. Pure motor stroke (MS) correlated significantly with the presence of the responsible lacune in the internal capsule ( P  = 0.000147) and with the stroke severity ( P  = 0.00724). No significant correlation was observed between the location of the lacunes and the other LS's.
Conclusion:  Pure MS has to be considered as the most specific lacunar syndrome.     

Motor cortex activation is preserved in patients with chronic hemiplegic stroke

Many central nervous system conditions that cause weakness, including many strokes, injure corticospinal tract but leave motor cortex intact. Little is known about the functional properties of surviving cortical regions in this setting, in part because many studies have used probes reliant on the corticospinal tract. We hypothesized that many features of motor cortex function would be preserved when assessed independent of the stroke-affected corticospinal tract. Functional MRI was used to study 11 patients with chronic hemiplegia after unilateral stroke that spared regions of motor cortex. Activation in stroke-affected hemisphere was evaluated using 3 probes independent of affected corticospinal tract: passive finger movement, a hand-related visuomotor stimulus, and tapping by the nonstroke index finger. The site and magnitude of cortical activation were similar when comparing the stroke hemisphere to findings in 19 control subjects. Patients activated each of 8 cortical regions with similar frequency as compared to controls, generally with a smaller activation volume. In some cases, clinical measures correlated with the size or the site of stroke hemisphere activation. The results suggest that, despite stroke producing contralateral hemiplegia, surviving regions of motor cortex actively participate in the same proprioceptive, visuomotor, and bilateral movement control processes seen in control subjects.     

Differential weakness of finger extensor muscles: A clinical pattern of multifocal motor neuropathy

Introduction: Several studies have suggested that differential weakness in muscles supplied by the same motor nerve supports the diagnosis of multifocal motor neuropathy (MMN). Methods: We describe the clinical, electrophysiological, neuroimaging, and laboratory findings of patients with a lower motor syndrome whose clinical presentation included differential finger extension weakness that we have seen in our neuromuscular clinic. Results: We identified 3 patients with hand weakness and 1 patient with asymmetric weakness of the upper extremity. Conduction blocks (CBs) were identified in 1 patient. Anti‐GM1 immunoglobulin M antibodies were detected in 2 of the 3 patients tested. Only 1 patient responded to intravenous immunoglobulin (IVIg). Rituximab was administered in another patient, but we did not detect a response. Conclusions: We suggest that differential finger extension weakness is a feature that may be seen in MMN, even in the absence of CB or response to IVIg. Muscle Nerve 55 : 433–437, 2017     

Clinical-computed tomographic correlations of lacunar infarction in the Stroke Data Bank

Lacunar stroke was diagnosed in 337 (26%) of the 1,273 patients with cerebral infarction among the 1,805 total in the Stroke Data Bank. We analyzed the 316 patients with classic lacunar syndromes. Among these, 181 (57%) had pure motor hemiparesis, 63 (20%) sensorimotor syndrome, 33 (10%) ataxic hemiparesis, 21 (7%) pure sensory syndrome, and 18 (6%) dysarthria-clumsy hand syndrome. No striking differences were found among the risk factors for the lacunar subtypes, but differences were found between lacunar stroke as a group and other types of infarcts. Compared to 113 patients with large-vessel atherosclerotic infarction, those with lacunar stroke had fewer previous transient ischemic attacks and strokes. Compared to 246 with cardioembolic infarction, patients with lacunar stroke more frequently had hypertension and diabetes and less frequently had cardiac disease. We found a lesion in 35% of the lacunar stroke patients' computed tomograms, with most lesions located in the internal capsule and corona radiata. The mean infarct volume was greater in patients with pure motor hemiparesis or sensorimotor syndrome than in those with the other lacunar stroke subtypes. In patients with pure motor hemiparesis and infarcts in the posterior limb of the internal capsule, there was a correlation between lesion volume and hemiparesis severity except for the few whose infarct involved the lowest portion of the internal capsule; in these patients severe deficits occurred regardless of lesion volume. Taken together, the computed tomographic correlations with the syndromes of hemiparesis showed only slight support for the classical view of a homunculus in the internal capsule.