Hypoglycemic hemiplegia: two cases and a clinical review

Hemiparesis With Hypoglycemia in a Child With Hypopituitarism Involving LHX4 Gene Deletion

We report a case of a 17-month-old boy with developmental delay who presented with acute-onset right-sided hemiparesis and hypoglycemia. Severe hypotension developed during his sedation for MRI and magnetic resonance angiography. Imaging revealed a hypoplastic pituitary gland within a shallow sella turcica and findings suggestive of moyamoya syndrome. Hemiparesis resolved 5 hours after correction of hypoglycemia with dextrose infusion, and severe hypotension improved with crystalloid fluids and vasopressors. Magnetic resonance angiography repeated 24 hours later revealed resolution of the vascular finding. Additional biochemical testing was consistent with hypopituitarism, and genetic evaluation revealed that the patient had a microdeletion including the LHX4 gene, which has been implicated in combined pituitary hormone deficiency type IV. Hypoglycemia frequently presents with autonomic or neuroglycopenic symptoms. However, when hypoglycemia presents with an isolated neurologic deficit like hemiparesis with preservation of alertness, it can be challenging to differentiate a cerebrovascular event from hypoglycemia-induced symptoms, leading to a delay in endocrine evaluation. Hypoglycemic hemiparesis is rare in childhood and is reported in children with diabetes mellitus or hyperinsulinism. This case expands the clinical spectrum of hemiparesis as a presenting sign of hypoglycemia in growth hormone and adrenocorticotropic hormone/cortisol deficiencies.

Hypoglycemic hemiparesis as stroke mimic with transient splenial lesion and internal capsule involvement: A reversible clinico-radiological concurrence

Hypoglycemia presents with a spectrum of neurological manifestations ranging from lightheadedness to confusion and coma. We report here the case of a 61-year-old woman with right hemiparesis presenting within the window period for stroke thrombolysis. MRI brain showed diffusion restriction in posterior limb of left internal capsule and splenium. Patient had documented hypoglycemia of 38 mg/dL. Patient's hemiparesis resolved after glucose correction, and radiological findings completely resolved after 10 days. We present this case to highlight the rare radiological finding of simultaneous internal capsule and splenium involvement in hypoglycemic hemiparesis and the importance to rule out stroke mimics to avoid unwanted thrombolysis.

Misdiagnosis of stroke

Rapid diagnosis of stroke is necessary for the timely delivery of thrombolysis and evaluation of novel therapies such as neuroprotection. An accurate clinical history and competent examination are key to identifying which patients are likely to have had a stroke and arranging and interpreting neuroimaging. Stroke symptoms are typically acute in onset, but are highly variable depending on the vascular territory affected. Common presenting symptoms are limb weakness, and speech and visual disturbances. Common stroke mimics are seizures, space occupying lesions, syncope, somatization and delirium secondary to sepsis. Stroke recognition instruments can help nonspecialists in the early diagnosis of stroke, with studies reporting sensitivity of over 90% and specificity of approximately 85% for some instruments. In patients with a clinical diagnosis of stroke, brain computed tomography or MRI is required to exclude some stroke mimics and differentiate ischemic from hemorrhagic stroke, which is key to providing appropriate therapies such as thrombolysis. In the future, plasma biomarkers may improve clinical diagnosis of stroke, but prospective studies are required to establish their utility. Clinical trials of acute stroke therapies need to ensure rapid accurate diagnosis of stroke using structured clinical assessments and appropriate imaging to achieve early treatment and avoid entry of stroke mimics into trials.

Neurologic damage in hypoglycemia

Hypoglycemia occurs in diabetic patients as a consequence of treatment with hypoglycemic agents, in insulinoma patients as a result of excessive insulin production, and in infants as a result of abnormal regulation of metabolism. Profound hypoglycemia can cause structural and functional disturbances in both the central (CNS) and the peripheral nervous system (PNS). The brain is damaged by a short and severe episode of hypoglycemia, whereas PNS pathology appears after a mild and prolonged episode. In the CNS, damaged mitochondria, elevated intracellular Ca2(+) level, released cytochrome c to the cytosol, extensive production of superoxide, increased caspase-3 activity, release of aspartate and glutamate from presynaptic terminals, and altered biosynthetic machinery can lead to neuronal cell death in the brain. Considering the PNS, chronic hypoglycemia is associated with delayed motor and sensory conduction velocities in peripheral nerves. With respect to pathology, hypoglycemic neuropathy in the PNS is characterized by Wallerian-like axonal degeneration that starts at the nerve terminal and progresses to a more proximal part of the axon, and motor axons to the muscles may be more severely damaged than sensory axons. Since excitatory neurotransmitters primarily involve the neuron in the CNS, this "dying back" pattern of axonal damage in the PNS may involve mechanisms other than excitotoxicity.

Multi-modal brain imaging showing brain damage to the orbitofrontal cortex and left hemisphere, in a case of prolonged hypoglycemia-induced transient hemiplegia followed by persistent encephalopathy

A 21-year-old left-handed male patient was admitted with a 19-h history of coma after substantial insulin injection for suicide attempt. Although the patient recovered from coma 3 days after injury, he experienced transient hemiplegia followed by permanent brain damage. Electroencephalogram (EEG), brain magnetic resonance imaging (MRI), and brain single-photon emission computed tomography (SPECT) identified the localization of this dysfunction, but consistency between clinical symptoms and brain images changed depending on the course of treatment. Transient hemiplegia corresponded to abnormal waveforms on EEG and decreased cerebral blood flow on SPECT, whereas persistent dysfunctions corresponded to abnormal brain regions on MRI and SPECT.

Stroke mimics

Stroke mimics are an important consideration for emergency physicians and physician extenders working in emergency departments. The emergency medicine physician must determine whether the acute neurologic deficits represent a transient event or a potential stroke. This article describes the common stroke mimic presentations by cause, including toxic-metabolic pathologies, seizure disorders, degenerative neurologic conditions, and peripheral neuropathies.

A case of hypoglycemic hemiparesis and literature review

An 89-year-old man with diabetes treated with metformin 500 mg/day and glimepiride 4 mg/day was hospitalized because of hypoglycemic right hemiparesis and dysarthria (casual glucose value 1.8 mmol/L), which resolved quickly following administration of 40 mL of 40% dextrose. Hemiparesis is a rare symptom (4.2%) of hypoglycemia. There are about 200 case reports of hypoglycemic hemiparesis. The average glucose level at which hemiparesis developed was 1.8 mmol/L. Right-sided hemiparesis predominated (R 66%; L 34%). On imaging studies, abnormal findings were frequently observed in the internal capsule or splenium of the corpus callosum. The mechanism of hemiparesis is not fully understood. The existence of cases in which hypoglycemia cannot be distinguished from stroke on imaging studies suggests the importance of measurement of the blood glucose level when the symptoms of stroke are first recognized.

Exercise-induced hypoglycemic hemiplegia in a child with type 1 diabetes: a rare find with multiple potential causative mechanisms

A 10-year-old boy known to have type 1 diabetes presented to the emergency department with history of sudden onset of right-sided hemiplegia after exercise. He did not respond to oral glucose administration, but had an almost immediate resolution of symptoms with intravenous bolus of dextrose. Hemiplegic hypoglycemia is a rare complication in diabetic children, mostly affects the right side of the body, and is rarely recurrent. Children have normal brain imaging and angiography testing, and electroencephalogram may show slow-wave activity. The recovery takes place within 24 hours, and the prognosis is excellent with no focal neurological deficits noted. Our patient responded within minutes to intravenous dextrose, which is unusual and has not been reported previously. The mechanisms leading to development of hypoglycemic hemiplegia are unclear, but may involve effects of hypoglycemia on intracellular signaling pathways or molecules on motor neurons, as recent studies have shown normal brain cell glucose uptake and metabolism in hypoglycemia. While hypoglycemic hemiplegia is rare, it is a frightening experience to caregivers, and efforts should concentrate on its prevention by preventing hypoglycemia.

Lateralization of hypoglycemic encephalopathy: evidence of a mechanism of selective vulnerability

BACKGROUND

One of the characteristics of hypoglycemic encephalopathy (HE) is selective vulnerability of different brain regions.

CASE REPORT

We observed a patient with unilateral HE affecting the right internal capsule and the subcortical white matter. The patient had a preexisting stroke in the opposite hemisphere. The hemisphere that was affected by HE exhibited greater regional blood flow (single positron-emission tomography) and higher fractional anisotropy (diffusion-tensor imaging) than the unaffected hemisphere.

CONCLUSIONS

This case suggests that the degree of metabolism required to maintain the function of brain structures and neuronal integrity is an important factor determining the selective vulnerability in HE.

Neurologic presentations of acid-base imbalance, electrolyte abnormalities, and endocrine emergencies

Accurate identification of nervous system dysfunction is vital in the assessment of any multisystem disorder. The neurologic manifestations of acid-base disturbances, abnormal electrolyte concentrations, and acute endocrinopathies are protean and typically determined by the acuity of the underlying derangement. Detailed history and physical examination may guide appropriate laboratory testing and lead to prompt and accurate diagnosis. Neurologic manifestations of primary and secondary systemic disorders are frequently encountered in all subspecialties of medicine. This article focuses on key neurologic presentations of respiratory and metabolic acid-base derangements and potentially life-threatening endocrinopathies.

Hypoglycemic hemiplegia: insulinoma masquerading as stroke

We report a patient with recurrent episodes of hemiplegia caused by hypoglycemia. Investigations revealed an insulinoma, which was surgically removed. After this, the blood glucose level normalized and the patient remained asymptomatic for 9 months. We discuss pathophysiological mechanisms whereby hypoglycemia might cause focal neurological deficit.

Recurrent hypoglycemic hemiparesis and aphasia in an adolescent patient

A 12-year-old diabetic female with right-side hemiparesis and aphasia occurring after a hypoglycemic episode is reported. Her clinical course improved over a 24-hour period, and further investigation revealed only electroencephalographic slowing, which was more prominent on the left. Ten months later, she had a recurrence of the same symptoms, which also resolved rapidly. This potential complication of hypoglycemia is often mistaken for a cerebrovascular accident.

Hypoglycemia in multiple trauma victims

The typical presentation of hypoglycemia involves a diaphoretic patient with a history of diabetes mellitus who is found with an altered mental status. The hypoglycemic patient's presentation may lead the physician to believe that the altered mentation may have been caused by some other condition. Hypoglycemia occurs rarely in the traumatic setting, yet is easily and rapidly diagnosed with bedside testing. A retrospective review was conducted in a university hospital emergency department (ED) (level 1 trauma center) of adult trauma patients with a Glasgow Coma Scale (GCS) score of <15 who had presented from July 1995 through August 1996. Hypoglycemia was defined as a serum glucose level of <60 mg/dL. A total of 926 patients (49% of all trauma cases encountered in the period) met entry criteria. Four (0.4%) cases of hypoglycemia were encountered in 1 nondiabetic and 3 diabetic patients; no patient had medical alert warnings. Rapid bedside screening identified 2 cases within a mean of 7 minutes after arrival; 1 patient had an improvement in mental status after dextrose therapy. Two cases were identified by formal laboratory analysis a mean of 35 minutes after ED arrival; dextrose therapy improved the mental status in 1 patient. These results show that hypoglycemia, rare in trauma patients with abnormal GCS scores, may mimic significant traumatic injury with mental status alterations. Physicians should consider such a diagnosis in patients with an abnormal GCS score and known risk situations for hypoglycemia, including diabetes mellitus and chronic alcohol use; in such cases, appropriate bedside screening should be performed after initial stabilization.

Muscle damage induced by experimental hypoglycemia

To determine organ damage due to hypoglycemia, we studied the effects of insulin dose and hypoglycemia duration on serum enzyme activity in rabbits. Thirty rabbits were randomly divided into five groups according to hypoglycemia duration and insulin dose: A2, hypoglycemia for 30 minutes with 2 U/kg insulin; A10, hypoglycemia for 30 minutes with 10 U/kg insulin; B2, hypoglycemia for 60 minutes with 2 U/kg insulin; B10, hypoglycemia for 60 minutes with 10 U/kg insulin; and C, no hypoglycemia with 10 U/kg insulin and 50% glucose. Insulin-induced hypoglycemia was reversed by intravenous injection of glucose. Alterations in serum enzyme activity and creatine kinase (CK) isoenzyme distribution were determined before and after insulin injection. Serum CK activity increased significantly in all hypoglycemic groups compared with preinjection values, and tended to remain high for 24 hours in both groups A10 and B10. Serum activity of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) increased only in group B10. In addition, the level of band 4 of serum CK isoenzymes, which exists predominantly in skeletal muscle and myocardium, increased significantly in group B10. These results suggest that the increase in both serum enzyme and CK band 4 isoenzyme activities during hypoglycemia is primarily due to damage in muscle rather than liver, and that the hypoglycemia duration and insulin dosage may influence the extent of organ damage.

Hypoglycemia presenting as acute respiratory failure in an infant

Hypoglycemia, a common metabolic abnormality seen in the pediatric population, is most often easily diagnosed and rapidly treated with satisfactory outcome. If not recognized and treated in prompt fashion, however, hypoglycemia may cause irreversible central nervous system injury or expose the patient to unnecessary procedures; it rarely results in death. The classic emergency department (ED) presentation of hypoglycemia, the diabetes mellitus patient using hypoglycemic therapy, is frequently encountered and adequately managed with excellent outcome. Alternatively, the patient may present to the ED in a fashion suggestive of a situation other than hypoglycemia. For example, the patient with an altered sensorium following a traumatic event, with a focal neurologic finding, or with bradycardia--all situations in which hypoglycemia is the causative issue--may not be immediately recognized as such a metabolic problem. This report presents a case of a 9-month-old boy who presented with acute respiratory failure and mental status change; the initial ED impression was one of pneumonia with sepsis. Further evaluation uncovered the actual reason for the mental status change and respiratory insufficiency: hypoglycemia was noted on laboratory analysis; no clinical evidence of pneumonia was found after thorough ED evaluation and a prolonged hospital stay. His mental status improved and his respiratory insufficiency resolved after glucose therapy. No other explanation for the respiratory failure was found during the hospital admission. It is imperative that the emergency physician consider hypoglycemia in all patients with any degree of mental status abnormality, even when the findings seem to be explained initially by other etiologies.

Acute hypoglycemia masquerading as head trauma: a report of four cases

Hypoglycemia, a commonly encountered metabolic emergency, is most often easily diagnosed and rapidly treated with satisfactory patient outcome. If not recognized and treated promptly, hypoglycemia may cause irreversible central nervous system injury; it rarely results in death. The classic presentation of hypoglycemia, a patient with diabetes mellitus on medical therapy (Insulin or oral hypoglycemic agents) who presents with an altered sensorium, is frequently seen in the emergency department (ED). Less often, patients with this metabolic emergency present to the ED in a manner suggestive of a situation other than hypoglycemia. Patients may present with seizure activity or focal neurological deficits, leading the physician to treat a primary neurological syndrome and not immediately recognize the primary cause of the problem. Alternatively, patients with hypoglycemia will present to the ED with an altered mental status after a traumatic event. The physician may again assume that the alteration in consciousness has resulted from a head injury and not a metabolic disorder. Four cases are presented in which the medical history of the event (i.e., trauma) suggested head injury as an explanation of the presentation when, in fact, hypoglycemia was responsible for the altered sensorium. The diagnosis of hypoglycemia is easily made with the performance of a bedside screening test which can be subsequently confirmed by laboratory blood analysis. It is imperative that emergency physicians consider hypoglycemia in all patients with any mental status abnormality, focal neurological deficit, or seizure activity, even when the findings seem to be explained initially by other etiologies.

Hypoglycemia manifested by sinus bradycardia: a report of three cases

Three cases are reported of hypoglycemia manifested by profound sinus bradycardia and fatigue, which responded to i.v. dextrose with prompt normalization of the cardiac rhythm. The cases involved 3 different patients and disease processes: a young female who had anorexia nervosa and profound malnutrition; an elderly, nondiabetic male who subsequently experienced a transient ischemic attack: and a patient who had diabetes mellitus managed with chronic, subcutaneous insulin administration. It is vitally important that the emergency physician recognize unusual clinical manifestations of hypoglycemia and fully evaluate such scenarios when hypoglycemia may occur. Untreated, hypoglycemia may result in significant chronic morbidity, and rarely, in death. Bradyarrhythmias--particularly sinus bradycardia--should be added to the list of potential clinical manifestations of hypoglycemia.

Plasma enzymic changes in insulin-induced hypoglycemia in experimental rabbits

In order to elucidate the effects of hypoglycemia on cardiac and skeletal muscle, plasma activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine kinase (CK) were assessed in rabbits with hypoglycemia induced by i.v. injection of insulin. After hypoglycemia lasting for more than 30 min, the plasma levels of ALT, AST and LDH rose significantly in 4 out of 5 rabbits reaching a peak at 24 hr. The plasma activity of CK rose remarkably and reached a peak at 6 hr after insulin injection in all rabbits. These results suggest prolonged hypoglycemia may cause myocardial and/or skeletal muscle damage, which can be ascertained by measuring plasma activities of the related enzymes.

Focal epileptic episodes associated with hypoglycemia in children with diabetes

Focal neurological deficits associated with hypoglycemia have been well described in adults with diabetes. We could find only one report of the association between focal epileptic episodes and hypoglycemia in children with diabetes. We describe 3 patients with seven focal epileptic episodes associated with hypoglycemia.

Regional cerebral blood flow during hypoglycaemia in children with IDDM

Hypoglycaemia may cause transient cognitive impairment and neurological deficits that are frequently unilateral. The effect of mild hypoglycaemia (serum glucose level 3.4 +/- 0.1 mmol/l; mean +/- SEM) on regional cerebral blood flow and cerebrovascular resistance was studied in eight right-handed children with insulin-dependent diabetes mellitus (age 14.9 +/- 0.7 years; diabetes duration 7.4 +/- 1.1 years; six males) using the intravenous xenon-133 clearance method. Global mean cerebral grey and white matter blood flow, adjusted to mean pCO2 of cohort, showed a trend towards an increase from 54.7 +/- 3.5 ml.100 g-1.min-1 at baseline euglycaemia to 58.0 +/- 4.1 ml.100 g-1.min-1 during hypoglycaemia (p = 0.075). Statistically significant changes were seen in global mean cerebral grey matter blood flow, as indexed by initial slope, which increased from 88.0 +/- 6.5 min-1 before hypoglycaemia to 96.3 +/- 7.2 min-1 during hypoglycaemia (p < 0.05). Cerebral grey matter blood flow was significantly higher in the right hemisphere compared to the left during hypoglycaemia (p < 0.01) but not at baseline euglycaemia. Measurements of global cerebrovascular resistance showed a borderline decrease from 1.64 +/- 0.11 to 1.54 +/- 0.11 mm Hg.ml-1.100 g-1.min-1 (p < 0.09). In conclusion, mild hypoglycaemia is associated with increases in cerebral blood flow which are greater in grey matter flow indices and in the right hemisphere. We speculate that asymmetrical cerebral blood flow changes may explain the frequent laterality of neurological deficits during severe hypoglycaemia.

Hypoglycemic hemiplegia: a case study

A 33-year-old man was seen in the emergency room with hypoglycemic hemiparesis of his left side. Hypoglycemic hemiparesis is an underrecognized manifestation of hypoglycemia and can mimic cerebrovascular disease, especially in the elderly. Although this is uncommon, hypoglycemia should be considered a part of the neurologic workup of any patient with a new onset of hemiparesis.

Hypoglycaemic hemiplegia: a repeat SPECT study

During a hypoglycaemic right hemiplegia induced by a deliberate overdose of oral hypoglycaemics, brain CT and angiography revealed no abnormalities. SPECTs made one day and six days later showed relative hypoperfusion in the left hemisphere. Repeat SPECT study suggested that the left hemisphere was more vulnerable than the right in the cerebral blood perfusion. This vulnerability might provoke the right hemiplegia in a critical condition, such as severe hypoglycaemia.

Paroxysmal dyskinesia associated with hypoglycemia

The association of movement disorders with hypoglycemia has been rarely noted in the past. We recently observed 2 patients with documented hypoglycemia and paroxysmal dyskinesias. One patient had evidence of an insulin-secreting tumor. The other patient had insulin-dependent diabetes, and also experienced recurrent episodes of hypoglycemic hemiparesis. Classical adrenergic symptoms of hypoglycemia were absent in both patients. Our observations support the concept that the development of neuroglycopenic symptoms cannot be predicted from blood glucose measurements alone, but must depend on other factors controlling the availability or metabolism of glucose in the brain.

Diabetes and stroke

Diabetes is a major risk factor for development of ischemic cerebrovascular disease. Patients with diabetes are at least two times more likely to have a stroke than nondiabetics. In addition, they are more likely to suffer increased morbidity and mortality after stroke. The mechanism of production of stroke secondary to diabetes may be due to cerebrovascular atherosclerosis, cardiac embolism, or rheologic abnormalities. The evaluation of cerebrovascular disease in diabetic patients is similar to the nondiabetic patient, with particular attention paid to adequate hydration prior to the administration of contrast agents. Treatment options for stroke in diabetics requires individualization but should include risk factor modification, and may include platelet antiaggregants, anticoagulation, or, in a well-defined subgroup, carotid endarterectomy.

Symmetry of cerebral blood flow and cognitive responses to hypoglycaemia in humans

A low blood glucose level is associated with impairment of higher cerebral function and an increase in cerebral blood flow. This study examined whether there are differences in the physiological responses to hypoglycaemia between the cerebral hemispheres. Eight healthy men participated in two hyperinsulinaemic glucose clamp studies: after 60 min at 4.5 mmol/l, blood glucose was either lowered to 2.0 mmol/l and "clamped" there for 60 min (hypoglycaemia) or continuously maintained at 4.5 mmol/l (euglycaemia). Cardiac output, middle cerebral artery velocity (transcranial Doppler) and cerebral blood flow (133-xenon inhalation) were measured during the studies. Neuropsychological tests were used to determine whether hypoglycaemia caused differential impairment of hemispheric cognitive function. Hypoglycaemia was associated with symmetrical impairment of cognitive function in both cerebral hemispheres and a rise in cardiac output (from 5.5 [0.2] to 8.7 [0.2] l.min-1, p < 0.0001, mean [standard error]), middle cerebral artery velocity (from 55 [2.6] to 64 [2.8] cm.s-1, p < 0.002), and global cerebral blood flow (from 56 [2.6] to 69 [2.9] ml.100 g-1.min-1, p < 0.005 compared to pre-insulin values). There were no differences in the blood flow response during hypoglycaemia between hemispheres and the increase in blood flow did not correlate with either the change in cardiac output or rise in plasma catecholamine levels. After 120 min of hyperinsulinaemic, euglycaemia, global cerebral blood flow rose significantly above baseline (from 58 [2.4] to 63 [2.2] ml.100 g-1.min-1, p < 0.05). In conclusion, using the techniques described, the physiological and cognitive responses of each cerebral hemisphere to hypoglycaemia were symmetrical.(ABSTRACT TRUNCATED AT 250 WORDS)

Hypoglycemia presenting as basilar artery thrombosis

BACKGROUND AND PURPOSE

Following our treatment of a patient with hypoglycemia-induced brain stem symptoms, we examined the possible mechanisms for hypoglycemia presenting as basilar artery disease.

CASE DESCRIPTION

We describe a patient who had progressive brain stem symptoms due to a diet-induced hypoglycemia initially diagnosed as basilar artery thrombosis. Symptoms ceased immediately after intravenous glucose.

CONCLUSIONS

Before invasive diagnostic and thrombolytic strategies are considered, hypoglycemia as a rare but important cause of acute brain stem dysfunction must be considered in patients suspected to suffer from basilar artery thrombosis.

Hypoglycemic hemiplegia in an adolescent with insulin-dependent diabetes mellitus: a case report and a review of the literature

A case of hypoglycemic hemiparesis in a fifteen-year-old girl with insulin dependent diabetes mellitus (IDDM) is described. The initial presentation included left facial paresis and muscular weakness of the left upper and lower extremities, associated with a blood glucose level of 31 mg/dL. The patient recovered completely after a glucose infusion. Her neurological examination became normal within 24 hours and remained so for a follow-up period of 6 months. Hypoglycemic hemiparesis is rarely described in children and adolescents.