Neuropsychiatric consequences of renal failure

Psychiatry in the renal unit

Consultation–liaison psychiatry in renal medicine provides a unique experience for the psychiatrist. There is the opportunity to work with a specialist multi-disciplinary team managing patients with chronic and complex physical problems in in-patient and out-patient settings. We aim to consider the common psychiatric problems experienced by renal patients and the particular problems that face the renal team and the liaising psychiatrist in relation to assessment and treatment.

Hypertensive Encephalopathy: A Case of a Male Who Bit Off His Fingers

Although altered consciousness and other neurologic manifestations are frequently seen in hypertensive encephalopathy, behavioral and psychotic symptoms are rarely seen. We describe a patient with no previous psychiatric history who was admitted for hypertensive crisis. A few days after admission, his blood pressure remained uncontrolled and he started to exhibit episodes of confusion, agitation, and psychosis. During one particular episode, he overcame multiple staff members and physical restraints to bite off two of his fingers without any signs of pain. Brain computed tomography (CT) was notable for possible posterior cerebral and cerebellar edema. His confusion and agitation gradually resolved with successful blood pressure management. This is the first reported case of extreme, agitated behaviors and auditory hallucinations in a patient with hypertensive crisis.

The two-way relationship between medical illness and late-life depression

This article reviews some common medical conditions and the interaction between those illnesses and depression in the geriatric population. The authors aim to help clarify the 2-way interaction between depression and these medical conditions, especially in older individuals, and impart some important diagnostic and treatment considerations to the practicing physician. The presence of multiple conditions further complicates treatment, as does associated medication use, substance abuse problems (often underappreciated in the elderly), age-related changes in sleep architecture, and an array of other psychosocial and environmental factors that can contribute to the development of depression.

Hypoalbuminaemia and impaired renal function are associated with increased anticholinergic drug prescribing

BACKGROUND

A higher anticholinergic risk score (ARS) is associated with an increased risk of anticholinergic adverse effects in elderly patients. It is unknown whether factors other than the use of anticholinergic drugs determine the ARS.

METHODS

A comprehensive medical record review was conducted in 155 consecutive hospitalised patients (median age 79.0 years, interquartile range 66.0-86.0). Information was collected on: demographics; clinical characteristics (including medications and their doses); history of anticholinergic-induced adverse effects; and biochemical markers of hepatic and renal function (serum albumin concentrations and estimated glomerular filtration rate, eGFR). The ARS was calculated for each patient using a standard scoring approach and Poisson regression was used for identifying variables associated with the ARS.

RESULTS

Patients with an ARS >or= 3 had a lower eGFR (p = 0.012) and were receiving more non-anticholinergic drugs (p < 0.001) than patients with an ARS < 3. In addition to being prescribed more anticholinergic drugs, patients with ARS >or= 3 were prescribed high doses of these drugs more often than patients with ARS < 3 (41.3% vs. 26.9%, p = 0.034). A higher number of non-anticholinergic drugs (p < 0.001), a lower serum albumin concentration (p = 0.014), and a lower eGFR (p = 0.012) were independently associated with a higher ARS.

CONCLUSIONS

Polypharmacy, hypoalbuminaemia and low eGFR are independently associated with the ARS. Patients with a higher ARS are also prescribed higher doses of anticholinergic medications than those with lower ARS.

Positive correlations between cerebral choline and renal dysfunction in chronic renal failure

INTRODUCTION

Cerebral metabolism in chronic renal failure (CRF) patients has not been fully evaluated. This study examined cerebral metabolites in CRF, using proton magnetic resonance spectroscopy (MRS).

METHODS

Subjects comprised 19 CRF patients and 21 healthy volunteers. Spectra were acquired from voxels of interest positioned in the parietal gray and white matter, and concentrations of the following cerebral metabolites were measured: N-acetyl group (NA), creatine + phosphocreatine (Cr), choline-containing compounds (Cho), myo-inositol and glutamate + glutamine. Among the 19 CRF patients, 9 who were started on hemodialysis (HD) underwent careful follow-up. Proton MRS was performed before and about 2 weeks after starting HD. In six patients in whom follow-up was possible, a third MRS was performed after about 18 months.

RESULTS

The NA/Cr ratio was not significantly changed in CRF. However, elevations in the Cho/Cr ratio were found in both gray and white matter compared with controls. To the best of our knowledge, this is the first report of positive correlations between the Cho/Cr ratio in both regions and serum osmotic pressure. Compared with baseline data, no significant changes in cerebral metabolite ratios were found about 2 weeks after starting HD. About 18 months after starting HD, however, the elevated Cho/Cr ratio was significantly reduced in the gray matter and tended to be reduced in the white matter.

CONCLUSIONS

Cho appear to play an important role in the regulation of cerebral metabolism to compensate for alterations in serum osmotic pressure in CRF, and HD may correct this abnormal cerebral metabolism.

Mechanism of increases in L-kynurenine and quinolinic acid in renal insufficiency

Marked increases in metabolites of the L-tryptophan-kynurenine pathway, L-kynurenine and quinolinic acid (Quin), were observed in serum and cerebrospinal fluid (CSF) of both the rat and human with renal insufficiency. The mechanisms responsible for their accumulation after renal insufficiency were investigated. In patients with chronic renal insufficiency, elevated levels of serum L-kynurenine and Quin were reduced by hemodialysis. In renal-insufficient rats, Quin and L-kynurenine levels in serum, brain, and CSF were also increased parallel to the severity of renal insufficiency. Urinary excretion of Quin (3.5-fold) and L-kynurenine (2.8-fold) was also increased. Liver L-tryptophan 2,3-dioxygenase activity (TDO), a rate-limiting enzyme of the kynurenine pathway, was increased in proportion to blood urea nitrogen and creatinine levels. Kynurenine 3-hydroxylase and quinolinic acid phosphoribosyltransferase were unchanged, but the activities of kynureninase, 3-hydroxyanthranilate dioxygenase, and aminocarboxymuconate-semialdehyde decarboxylase (ACMSDase) were significantly decreased. Systemic administrations of pyrazinamide (ACMSDase inhibitor) increased serum Quin concentrations in control rats, demonstrating that changes in body ACMSDase activities in response to renal insufficiency are important factors for the determination of serum Quin concentrations. We hypothesize the following ideas: that increased serum L-kynurenine concentrations are mainly due to the increased TDO and decreased kynureninase activities in the liver and increased serum Quin concentrations are due to the decreased ACMSDase activities in the body after renal insufficiency. The accumulation of CSF L-kynurenine is caused by the entry of increased serum L-kynurenine, and the accumulation of CSF Quin is secondary to Quin from plasma and/or Quin precursor into the brain.

Occurrence of Neuropsychiatric Symptoms at Low Levels of Occupational Exposure to Organic Solvents and Relationships to Health, Lifestyle, and Stress

The objective of this study was to elucidate the effects of alcohol consumption, medical disorders, stressful life events, and solvent exposure on neuropsychiatric symptoms in a population with low levels of occupational exposure to organic solvents. The prevalence of neuropsychiatric symptoms was assessed by Questionnaire 16 (Q16) in 54 miners under notice of dismissal and 124 men in an age-matched random sample from the local population. When the Q16 results were dichotomized at six symptoms (of the 16 possible), regular use of medicine was significantly related to the Q16 score, with an adjusted odds ratio (adjOR) of 4.0, 95% confidence interval (95% CI) 1.2-13. There were also positive relationships to the number of years in work with exposure to organic solvents (adjOR 2.2 per 10 years, 95% CI 1.3-3.8), liters of pure alcohol consumed per month (adjOR 2.8, 95% CI 0.78-10), and unemployment (adjOR 2.4, 95% CI 0.80-7.2). The influences on neuropsychiatric symptoms of various common exposures other than occupational solvent exposure must be considered when questionnaires are used for screening or for studies of possible neurotoxic effects in solvent-exposed workers.

The management of treatment-resistant depression in the medically ill

There are a few well-designed studies to systematically assess treatment-resistant depression in the medically ill patient. Psychiatrists, however, do have extensive clinical experience in treating depression in the medical patient. This experience can be useful in helping to determine treatment resistance and in selecting consequent treatment choices. A decision tree is offered in Table 1 to clarify the questions the clinician must answer. The first step is to evaluate the role of the medical illness and to decide whether or not treating that effectively will also clear the depression. Physicians may find it helpful to use a decision tree in initiating treatment of patients with depression and physical illness. Once it has been clarified that the diagnosis of depression is a correct one and that an antidepressant medication is in order, consideration of safety, side effects, and other current prescriptions used by the patient must occur. Drug-drug interactions as well as changes in the clearance of medications are critical to the effectiveness of the choice and tolerability for the patient. An antidepressant agent needs to be given for an adequate time with optimization of dosing. Augmenting a medication to increase its therapeutic action could be tried if one agent alone is not effective. An alternative approach is that the second drug selected might affect different neurotransmitters, and the combination of mechanisms would result in resolution of symptoms. Adding psychotherapy, especially when social supports are lacking, can be particularly helpful. ECT is an important consideration for severe depression when suicidal concerns are imminent or the patient has not responded to pharmacotherapy trials. While we await further studies of treatment-resistant depression in large enough numbers of patients with particular illnesses, we can use these guidelines to direct our decisions to switch or augment our initial choices to provide the safest, most effective care possible.