Neurologic manifestations of chronic pulmonary insufficiency

Obstructive Sleep Apnea and Neurocognitive Dysfunction in Edentulous Patients

PURPOSE

To record the incidence of cognitive dysfunction in edentulous patients suffering from obstructive sleep apnea (OSA) and establish a plausible hypothesis to explain the correlation of cognitive dysfunction and OSA.

MATERIALS AND METHODS

In this study, 315 edentulous patients (aged 60 to 65 years) visiting the outpatient department at Saraswati Dental College, Lucknow were recruited from January 2013 to October 2015. Prosthodontic Diagnostic Index (PDI) classification was used to assess the intraoral condition to relate it with the span of edentulousness. The BERLIN questionnaire and Epworth Sleepiness Scales were used to diagnose sleep-disordered breathing, following which the patients were put through all-night polysomnography. The apnea-hypopnea index (AHI) scores were derived. Mild and moderate OSA patients were classified into mild, moderate, and severe cognitive dysfunction based on SGRQ-C and SCD. Data were tabulated according to a new classification (Cognitive Dysfunction of Dental Sleep Medicine Patients [CDDSMP] Classification) designed specifically for this study. Data were analyzed using SPSS v15.0. Scores were tabulated as mean ± SD and median [IQR] values. Change from baseline was analyzed using Wilcoxon signed rank test.

RESULTS

Mean scores at different time intervals were 3.03 ± 1.76 (3 months), 2.98 ± 1.80 (6 months), and 2.81 ± 1.84 (9 months). The median [IQR] values of scores at all time intervals except 9 months were 3 [1 to 5]. At 9 months, median [IQR] was 2 [1 to 5]. A significant change in scores was observed in the 3-month interval (p ≤ 0.001).

CONCLUSIONS

The severity of OSA and neurocognitive dysfunction could be directly related to the PDI classification and the span of edentulousness of the patient and modified mandibular advancement device treatment significantly improved the patients' condition, which was reflective from 3 months post-intervention itself.

Asterixis: a study of 103 patients

In 1949, asterixis was first described in patients with hepatic encephalopathy. It was quickly recognized that this phenomenon also occurs in other generalized encephalopathies and sometimes results from structural brain lesions. This paper is a study of asterixis in the general neurology clinic and on the inpatient neurology consultation service. The neurologists recorded the findings on inpatients and clinic patients for 12 consecutive months. Of the 1,109 inpatients with adequate examination, asterixis was documented in 97. Eighteen of the 97 cases were unilateral (18.6%) and 79 cases were bilateral (81.4%). Of the 614 outpatient visits with well documented examination, 6 (1%) individuals had asterixis. Since a small number of patients were examined more than once, the study yielded 103 individuals with adequate data for analysis. Asterixis resulted from varied causes: medications, renal disorder, hepatic dysfunction, pulmonary insufficiency, stroke and other brain lesions (including malignancy, subdural hematoma, and epidural abscess). Asterixis occurred in various patterns: in some cases it was easier to elicit in the upper extremities, in some it was easier to elicit in the lower limbs, and some it was solely or predominantly unilateral. The findings are discussed in light of the literature on asterixis with regard to its varied causes, patterns and presentations. Lastly, asterixis is examined from a historical perspective and the terminology is elucidated.

Metabolic encephalopathies

Kinnier Wilson coined the term metabolic encephalopathy to describe a clinical state of global cerebral dysfunction induced by systemic stress that can vary in clinical presentation from mild executive dysfunction to deep coma with decerebrate posturing; the causes are numerous. Some mechanisms by which cerebral dysfunction occurs in metabolic encephalopathies include focal or global cerebral edema, alterations in transmitter function, the accumulation of uncleared toxic metabolites, postcapillary venule vasogenic edema, and energy failure. This article focuses on common causes of metabolic encephalopathy, and reviews common causes, clinical presentations and, where relevant, management.

Cognition and chronic hypoxia in pulmonary diseases

Lung disease with chronic hypoxia has been associated with cognitive impairment of the subcortical type.

Subclinical encephalopathy in chronic obstructive pulmonary disease

BACKGROUND

Clinical and experimental evidence suggests that chronic obstructive pulmonary disease (COPD) is associated with a variety of mental symptoms that range from cognitive slowing to mental confusion and dementia.

PURPOSE

To test the hypothesis that COPD leads to cognitive impairment in the absence of acute confusion or dementia.

METHOD

The global cognitive status of 30 patients with COPD without dementia or acute confusion and 34 controls was assessed with a Brazilian version of the Mini-Mental State Exam (MMSE).

RESULTS

The MMSE scores were significantly lower in the patient group and inversely related to the severity of COPD. This finding could not be attributed to age, education, gender, daytime sleepiness, hypoxemia, chronic tobacco use, or associated diseases such as diabetes, depression, high blood pressure or alcoholism.

CONCLUSION

These results suggest the existence of a subclinical encephalopathy of COPD characterized by a subtle impairment of global cognitive ability.

Doing What I Like

I have spent my entire professional life at Harvard Medical School, beginning as a medical student. I have enjoyed each day of a diverse career in four medical subspecialties while following the same triad of preclinical areas of investigation—cysteinyl leukotrienes, mast cells, and complement—with occasional translational opportunities. I did not envision a career with a predominant preclinical component. Such a path simply evolved because I chose instinctively at multiple junctures to follow what proved to be propitious opportunities. My commentary notes some of the highlights for each area of interest and the mentors, collaborators, and trainees whose counsel has been immensely important at particular intervals or over an extended period.

Neurologic complications of respiratory disease

The respiratory system and the central nervous system are interconnected in a delicate balance; disorders in this equilibrium can have devastating consequences. Respiratory dysfunction, whether acute or chronic, may cause neurologic disease, including headache, encephalopathy, and in extreme cases, coma and death. This article will discuss abnormalities in ventilation and gas exchange, their subsequent pathophysiologic effects on the nervous system, and mechanisms of treatment for these disorders.

Topographic quantitative analysis of the intrinsic alpha rhythm in chronic obstructive pulmonary disease

Twenty-two patients with documented COPD and no other significant illnesses were studied to assess the effect of varying degrees of COPD on the intrinsic alpha rhythm. The severity of COPD was determined by spirometry with assessment of FEV1, FVC, and FEV1/FVC. The alpha frequency for COPD patients was slower than that which characterizes age equated normals and averages 1.6 S.D. below normative data base mean values (range -0.43 S.D. to -1.85 S.D.). Impairment of pulmonary functioning significantly correlated with the degree of alpha frequency slowing over the posterior cortical regions, and the slowest alpha frequencies occurred in those COPD patients with the lowest FEV1/FVC ratios. Impairment of cognitive functioning is thus an important clinical consideration in treatment of patients with COPD but may go unrecognized until late in the course of the disease.

Acid-base disorders in medicine

The practice of internal medicine involves daily exposure to abnormalities of acid-base balance. A wide variety of disease states either predispose patients to develop these conditions or lead to the use of medications that alter renal, gastrointestinal, or pulmonary function and secondarily alter acid-base balance. In addition, primary acid-base disease follows specific forms of renal tubular dysfunction (renal tubular acidosis). We review the acid-base physiologic functions of the kidney and gastrointestinal tract and the current understanding of acid-base pathophysiologic conditions. This includes a review of whole animal and renal tubular physiologic characteristics and a discussion of the current knowledge of the molecular biology of acid-base transport. We stress an approach to diagnosis that relies on knowledge of acid-base physiologic function, and we include discussion of the appropriate treatment of each disorder considered. Finally, we include a discussion of the effects of acidosis and alkalosis on human physiologic functions.

Neurological improvement following respiratory support in syringomyelia: case report

Respiratory failure in syringomyelia has rarely been reported. We report a patient with syringomyelia who showed some neurological improvement after intermittent respiratory support with negative and positive pressure ventilation.

Medical therapy of altitude illness

Acute mountain sickness (AMS) and high-altitude pulmonary edema (HAPE) continue to cause significant morbidity and occasional deaths among mountain recreationists and residents. Descent to lower altitude is still considered the treatment of choice, but an increased role for medical therapy is emerging. Acetazolamide is currently the drug of choice for prevention of AMS, and probably HAPE as well. Numerous studies have demonstrated the drug's effectiveness when it is started 12 to 24 hours before ascent. Suggestions for indications, dosage, and regimen vary with different authors. Lower dosage offers adequate protection with fewer side effects. Acetazolamide has still not been adequately studied for treatment of altitude illness. Oxygen effectively treats HAPE and mild AMS, but is not as useful for cerebral edema. Dexamethasone recently was found effective for treatment of AMS, including early cerebral edema, but not for advanced cerebral edema. Side effects limit its use for prophylaxis, but dexamethasone offers an alternative to acetazolamide for those with sulfa intolerance.

Papilloedema and respiratory failure

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Portal-systemic encephalopathy: neuropsychiatric manifestations

Portal-systemic encephalopathy, which occurs as a consequence of cirrhosis of the liver, is associated with a variety of neuropsychiatric symptoms. Problems related to the differential diagnosis and medical management of portal-systemic encephalopathy, as compared to other more usual psychiatric disorders, are discussed. Also addressed are issues of particular concern to psychiatry, such as the use of pharmacotherapeutics and the rehabilitation of alcoholism, which are commonly seen in individuals with portal-systemic encephalopathy and liver disease, as well as in the general psychiatric patient population.

Evidence of motor neuron involvement in chronic respiratory insufficiency

Nineteen patients with chronic respiratory insufficiency, mean age 61.4 +/- 12.2, have been investigated with pulmonary function tests, clinical neurological examination and neurophysiological methods including motor and sensory conduction studies and needle electromyography. None of them had conditions known to affect the peripheral nervous system such as diabetes, alcoholism, or uraemia. The motor and sensory conduction studies showed only a reduced mean amplitude of the ulnar nerve SAP and of the compound muscle action potential of the APB and EDB muscles. The EMG was abnormal in 94.7% of the cases and showed an increased percentage of polyphasic potentials and a reduced recruitment pattern of motor units firing at high frequency. The data seem to support the hypothesis of an involvement of motor neurons in this condition although the evidence for a neuropathy is lacking.

Papilloedema associated with respiratory failure

A case of papilloedema secondary to respiratory failure is reported which caused considerable diagnostic difficulty and led to extensive neurological investigation. Neurological complaints of headache and visual impairment overshadowed respiratory symptoms and were associated with gross haemorrhagic papilloedema. The case is compared with previous reports and the pathogenesis of papilloedema in respiratory failure is reviewed briefly. The similarity between the pathogenesis of this condition and benign intracranial hypertension is discussed.

Drug-induced encephalopathy in patients on maintenance haemodialysis

In five patients who had been on chronic maintenance haemodialysis for more than eight months a syndrome involving altered consciousness, asterixis, and abnormal electroencephalogram developed after they had been given flurazepam and diazepam. All five patients were adequately treated by haemodialysis. Hepatic, pulmonary, and cardiac decompensation were not present. The encephalopathy and other abnormalities cleared when the drugs were withdrawn. Symptoms were also produced by accidental rechallenge.

Secondary metabolic encephalopathy. Diagnosis and treatment

Secondary metabolic encephalopathy is a diffuse disorder of the brain caused by an extracerebral process. Underlying causes include oxygen deprivation, systemic metabolic disease, and drug intoxication. Symptoms and signs usually suggest a generalized disturbance of brain function: alterations in the level of consciousness; diffuse and, occasionally, focal motor abnormalities; and seizures. Electroencephalography in most instances gives evidence of generalized neuronal disturbance. Early diagnosis is important because encephalopathy secondary to an extracerebral process is potentially reversible. Treatment is directed toward reversal or control of the underlying process, supportive care, and prevention of complications such as infection, electrolyte imbalance, and cerebral edema.

Cerebral form of high-altitude illness

Twelve cases of severe altitude illness are reported in which the neurological signs and symptoms dominated the clinical picture. Pulmonary oedema, retinal haemorrhage, thrombophlebitis and pulmonary embolism, bronchopneumonia, and coronary-artery disease were also present in several of the patients but the primary problem seems to have been cerebral oedema. Other published cases support this impression. Patients who were returned to low altitude early in the disease fared well; two patients died, and in both cases evacuation had been delayed. The most effective prevention lies in slow ascent, though in one case reported here the rate of climb was well within the recommended limit. Recommended management is rapid descent to low altitude at earliest indication of cerebral or pulmonary oedema, intravenous dexamethasone or betamethasone in large doses, hydration, diuresis (frusemide has been most used), and perhaps other intravenous therapy with hyperosmolar materials such as mannitol, urea, 50% saline, or 50% sucrose. Prognosis is good if descent and treatment are started early, but permanent damage may be anticipated if the patient is unconscious for any prolonged period before descent.

Alterações do líquido céfalorraqueano e perturbações do sistema nervoso central em distúrbios do controle hidrogênio-iônico: estudo da relação cloretos/CO2 total

O LCR constitui um meio muito pobre em proteínas e o seu poder tampão depende fundamentalmente da relação pCO2/HCO3-. O LCR é, por assim dizer, uma solução salina bicarbonatada à qual se juntam pequenas quantidades de outros componentes iônicos e moleculares. Admite-se que a barreira hemato-encefálica protege o sistema nervoso central contra as variações súbitas do equilíbrio hidrogênio-iônico. Ela apresenta uma lenta permeabilidade às variações de concentrações dos iontes HCO3-, Cl-, H+, Na+, de que resulta proteção do pH do LCR, e fácil permeabilidade ao gás CO2 de sorte a favorecer rápidos ajustes com o sangue. Estes fatos explicam porque, por vezes, podem ser observadas variações divergentes do pH de um lado e de outro da barreira. Por motivo de sua importante função fisiológica na regulação da respiração, o LCR está muito bem protegido em relação à estabilidade de seu pH. Além disto o pH do LCR indica mais fielmente as modificações ácido-básicas do tecido cerebral que o pH do sangue. Os distúrbios graves do controle hidrogênio-iônico determinam perturbações da função cerebral com manifestações neurológicas e psíquicas. Por estes motivos as determinações do pH, pCO2, e CO2 total do LCR têm uma grande importância para a interpretação dos problemas fisiopatológicos que ocorrem no sistema nervoso central, para o conseqüente diagnóstico e para a correta indicação terapêutica. Pouco se sabe sobre as perturbações da função do sistema nervoso central em pacientes com acidose metabólica; já se tem descrito distúrbios neurológicos e mentais em pacientes com alcalose respiratória e alcalose metabólica; entretanto, é em relação à acidose respiratória que a literatura é mais extensa. Na acidose respiratória decorrente da insuficiência ventilatória pulmonar grave pode-se observar uma síndrome de hipertensão endocraniana devida à ação vasodilatadora do CO2 e estes pacientes são por vezes encaminhados aos serviços neurológicos com a suspeita de tumor encefálico. O propósito do presente trabalho foi o de determinar a relação cloretos/ CO2 total no LCR normal e no LCR de pacientes neurológicos com distúrbios mais comuns do controle hidrogênio-iônico, para se poder avaliar o seu valor prático no exame de rotina. O material deste estudo é constituído por 58 observações, sendo 37 de pessoas normais e 21 de pacientes com distúrbios graves do controle hidrogênio-iônico, dos quais 11 apresentavam acidose respiratória e 10 acidose metabólica decorrente de coma diabético. Em condições normais, a relação cloretos/CO2 total no LCR está compreendida entre os valores de 4.8 a 5.8. Nos distúrbios do controle hidrogênio-iônico, particularmente naqueles casos crônicos e graves, verificam-se alterações das taxas de cloretos e de CO2 total, cujas concentrações variam de modo compensatório, umas em sentido oposto às outras, nestes ajustamentos ácido-básicos. Na acidose respiratória o LCR apresenta acentuada diminuição da taxa de cloretos com aumento compensatório da concentração do CO2 total. Nestes casos a relação variou de 2.0 a 4.7. Na acidose metabólica, como exemplo aquela que ocorre em pacientes em coma diabético, observa-se diminuição acentuada da concentração do CO2 total e aumento da taxa de cloretos. Nestes casos, os valores da relação cloretos/CO2 total estavam compreendidos entre 6.5 a 22.

Restless legs syndrome in chronic pulmonary disease

Eight consecutive patients referred for neurological opinion because of very severe "restless legs" all suffered from chronic pulmonary disease. It was considered that the restless legs syndrome was not a metabolic consequence of respiratory failure but a nervous manifestation of their invalidism.