Virtual twins for model-informed precision dosing of clozapine in patients with treatment-resistant schizophrenia

Model-informed precision dosing using virtual twins (MIPD-VTs) is an emerging strategy to predict target drug concentrations in clinical practice. Using a high virtualization MIPD-VT approach (Simcyp version 21), we predicted the steady-state clozapine concentration and clozapine dosage range to achieve a target concentration of 350 to 600 ng/mL in hospitalized patients with treatment-resistant schizophrenia (N = 11). We confirmed that high virtualization MIPD-VT can reasonably predict clozapine concentrations in individual patients with a coefficient of determination (R2 ) ranging between 0.29 and 0.60. Importantly, our approach predicted the final dosage range to achieve the desired target clozapine concentrations in 73% of patients. In two thirds of patients treated with fluvoxamine augmentation, steady-state clozapine concentrations were overpredicted two to four-fold. This work supports the application of a high virtualization MIPD-VT approach to inform the titration of clozapine doses in clinical practice. However, refinement is required to improve the prediction of pharmacokinetic drug-drug interactions, particularly with fluvoxamine augmentation.

Patient Pain and Satisfaction With 10, 30, and 70 mL Transcervical Foley Balloons for Cervical Ripening During Induction of Labor

Objective To assess patient pain and satisfaction and time to delivery following transcervical Foley catheter balloon inflation to 10, 30, or 70 mL with simultaneous administration of oxytocin. Methods We performed a randomized prospective study with 30 or 70 mL transcervical Foley balloon catheters in combination with oxytocin during labor induction at term. A 10 mL group was included as a sham control group. Time to delivery was measured, and a patient questionnaire was administered at the time the catheter was expelled to determine patient pain and satisfaction. Results In 120 enrolled patients, there was a non-significant trend toward reduced time to delivery in the large Foley balloon group (10 mL: 30:45 ± 38:53, 30 mL: 26:41 ± 20:53, and 70 mL 22:40 ± 15:35, hh:mm, P = 0.412). The pain score at the time the balloon was expelled was significantly higher in the 70 ml group compared to the 10 ml and 30 ml groups (P = 0.004 and P = 0.034, respectively). We found no other differences in patient satisfaction or pain scores at the time of placement of the Foley catheter for the three groups. Conclusion Small gains in time to delivery should be balanced against patient experiences, and expectations of pain during the ripening process should be addressed at the time of Foley insertion.

Subjective cognitive functioning, depressive symptoms, and objective cognitive functioning in people with treatment-resistant psychosis

Introduction: Relationships between subjective cognitive functioning (SCF), objective cognitive functioning (OCF), and depressive symptoms are poorly understood in treatment-resistant psychosis (TRP). This study (a) compares SCF in TRP using positively and negatively worded scales, (b) assess these scales' accuracy, and (c) explores the association between these scales and depressive symptoms. We hypothesised that both SCF scales would be highly correlated, minimally associated with OCF, and similarly associated with depressive symptoms. Methods: Archival clinical data from 52 TRP inpatients was utilised. OCF composite scores were derived from a broad neuropsychological battery. SCF was assessed using the norm-referenced PROMIS 2.0 Cognitive Abilities (positively worded) and Concerns (negatively worded) subscales. A depressive symptom score was derived from the Positive and Negative Syndrome Scale. Results: SCF ratings were higher in patients than OCF. There was a small but significant correlation between PROMIS subscales (r = .30). Neither PROMIS subscale was associated with OCF (r = -.11, r = .01). Depressive symptoms were correlated with the positively (r = -.29) but not negatively worded scale (r = -.13). Conclusion: Individuals with TRP inaccurately rate their cognitive functioning and tend to overestimate their ability. Positively and negatively worded SCF scales associate variably with depressive symptoms, indicating they may not be used interchangeably in TRP.

Whole-genome sequencing analysis of clozapine-induced myocarditis

One of the concerns limiting the use of clozapine in schizophrenia treatment is the risk of rare but potentially fatal myocarditis. Our previous genome-wide association study and human leucocyte antigen analyses identified putative loci associated with clozapine-induced myocarditis. However, the contribution of DNA variation in cytochrome P450 genes, copy number variants and rare deleterious variants have not been investigated. We explored these unexplored classes of DNA variation using whole-genome sequencing data from 25 cases with clozapine-induced myocarditis and 25 demographically-matched clozapine-tolerant control subjects. We identified 15 genes based on rare variant gene-burden analysis (MLLT6, CADPS, TACC2, L3MBTL4, NPY, SLC25A21, PARVB, GPR179, ACAD9, NOL8, C5orf33, FAM127A, AFDN, SLC6A11, PXDN) nominally associated (p < 0.05) with clozapine-induced myocarditis. Of these genes, 13 were expressed in human myocardial tissue. Although independent replication of these findings is required, our study provides preliminary insights into the potential role of rare genetic variants in susceptibility to clozapine-induced myocarditis.

First Whole Transcriptome RNAseq on CHD8 Haploinsufficient Patient and Meta-Analyses Across Cellular Models Uncovers Likely Key Pathophysiological Target Genes

In 2019, we confirmed that the haploinsufficiency of CHD8 does indeed cause the novel syndromic neurodevelopmental disease we first discovered a dozen years before. Here, we report the first whole transcriptome RNAseq gene expression profiling for a patient with this new syndrome, as a preliminary exploration of potential pathophysiological mechanisms. We compared our patient transcriptome profile with that of all publicly available RNAseq datasets from human cellular models including neuronal progenitor cells, neurons and organoids. We compared differential gene expression profiles overall and conducted phenotype-informed data filtration based on the characteristic syndrome presentation. We found that concordance among differential gene expression profiles was poor across all datasets. Nevertheless, remarkably, we show that the patient blood differential gene expression profile most resembled that of the neuronal cell model, a finding that encourages further transcriptome profiling using patient blood samples. In addition, our custom phenotype-informed analyses yielded important, differentially expressed syndrome pathophysiology target genes. Finally, we note that genes dysregulated due to CHD8 heterozygous deletion are linked to known neurological as well as oncological pathways.

Treatment-resistant psychotic symptoms and early-onset dementia: A case report of the 3q29 deletion syndrome

The 3q29 deletion is a rare copy number variant associated with neurodevelopmental and psychiatric disorders, including a >40-fold increased risk for schizophrenia. Current understanding of the clinical phenotype is derived primarily from published cases of patients in childhood or early adolescence. Symptoms include mild to moderate learning disability, developmental delay, facial dysmorphism, microcephaly, ocular disorders, and gastrointestinal abnormalities. There is, however, a lack of detailed longitudinal case studies describing 3q29 deletion syndrome in adults with psychosis. In this case report, we describe the lifetime clinical portrait of a 57-year-old woman with 3q29 deletion syndrome, treatment-resistant psychotic symptoms, multiple medical comorbidities, and a previously unreported co-occurrence of early-onset dementia.

Improved strength on 5-hydroxytryptophan and carbidopa in spinal cord atrophy

There is ample evidence of an important role of descending serotonergic projections in modulating spinal motor neuron activation and firing, and experimental studies suggest that 5-HT receptor stimulation can improve motor function after spinal cord injury; however, relevant clinical data is sorely lacking. We describe two sisters with hemiplegic migraine, low CSF and platelet serotonin levels, and progressive spastic paraparesis associated with profound spinal cord atrophy whose lower extremity strength and ambulation responded to a precursor replacement strategy (5-hydroxytryptophan and carbidopa administration), an approach that may have broader applicability in myelopathies of diverse etiology where descending serotonergic projections are compromised.

Liver Transplant Can Resolve Severe Neuropsychiatric Manifestations of Wilson Disease: A Case Report

Although liver transplant for decompensated cirrhosis secondary to Wilson disease is well accepted, the use of transplant for patients with severe neurologic manifestations of this condition remains controversial, and these can be perceived as a contraindication. Here, we describe a 45-year-old woman who presented with an incidental hepatocellular carcinoma at the time of transplant. The patient had severe neurologic manifestations of Wilson disease pretransplant, including dysarthria, hyperreflexia, asymmetrical ataxia, tremor, bradyphrenia, and shuffling gait. She underwent successful transplant from a hepatic and surgical standpoint, but her postoperative course was marked by protracted mutism, hypophonia, and fluctuating akinesia and immobility that did not respond promptly to withdrawal of calcineurin inhibitors or pramipexole but did respond robustly to amantadine. At 9 months posttransplant, there was marked neurologic improvement, and, at 18 months, she exhibited subtle memory and organizational difficulties but was fully ambulatory and otherwise completely functional. Our experience suggests that even patients with severe neurologic Wilson disease may recover after transplant, albeit slowly, demonstrating the need for a multidisciplinary approach, including pre- and posttransplant neurologic and neuropsychiatric consultations.

Classification images of two right hemisphere patients: a window into the attentional mechanisms of spatial neglect

While spatial neglect most commonly occurs after right hemisphere lesions, damage to diverse areas within the right hemisphere may lead to neglect, possibly through different mechanisms. To identify potentially different causes of neglect, the visual information used (the 'perceptual template') in a cueing task was estimated with a novel technique known as 'classification images' for five normal observers and two male patients with right-hemisphere lesions and previous histories of spatial neglect (CM, age 85; HL, age 69). Observers made a yes/no decision on the presence of a 'White X' checkerboard signal (1.5 degrees ) at one of two locations, with trial-to-trial stimulus noise added to the 9 checkerboard squares. Prior to the stimulus, a peripheral precue (140 ms) indicated the signal location with 80% validity. The cueing effects and estimated perceptual templates for the normal observers showed no visual field differences. Consistent with previous studies of spatial neglect, both patients had difficulty with left (contralesional) signals when preceded by a right (ipsilesional) cue. Despite similar behavioral results, the patients' estimated perceptual templates in the left field suggested two different types of attentional deficits. For CM, the left template matched the signal with left-sided cues but was opposite in sign to the signal with right-sided cues, suggesting a severely disrupted selective attentional strategy. For HL, the left templates indicated a general uncertainty in localizing the signal regardless of the cue's field. In conclusion, the classification images suggested different underlying mechanisms of neglect for these two patients with similar behavioral results and hold promise in further elucidating the underlying attentional mechanisms of spatial neglect.

Accuracy of four clinical diagnostic criteria for the diagnosis of neurodegenerative dementias

OBJECTIVE

To evaluate the inter-rater reliability and validity of clinical diagnostic criteria for neurodegenerative dementias.

BACKGROUND

Inter-rater accuracy of the diagnosis of AD has been explored, but there are few accuracy studies for progressive supranuclear palsy (PSP) and frontotemporal lobe dementia (FTD). Furthermore, there have been no simultaneous accuracy studies in a mixed sample of patients with cortical and subcortical neurodegenerative processes.

METHODS

Four experienced clinicians reviewed first-visit clinical data abstracted from the records of 40 pathologically diagnosed demented subjects. They were asked to apply the NINCDS-ADRDA criteria for AD, the NINDS-SPSP clinical criteria for PSP, the Lund and Manchester criteria for FTD, and the Consensus Guidelines for the Clinical Diagnosis of Dementia with Lewy Bodies (DLB).

RESULTS

The generalized K for AD was 0.73, for PSP 0.82, for FTD 0.75, and for DLB 0.37. The K pool test showed a statistically significant difference between DLB and the other disease processes, and no differences were observed among AD, FTD, and PSP. The mean sensitivity for AD was 95%, for PSP 75%, for FTD 97%, and for DLB 34%. The mean specificity for AD was 79%, for PSP 98.5%, for FTD 97%, and for DLB 94%.

CONCLUSIONS

We found improved inter-rater reliability for the diagnosis of AD among clinicians compared with earlier studies. Similarly, there was a near-perfect and substantial inter-rater agreement for the diagnosis of PSP and FTD. The sensitivity for the diagnosis of AD was high, although clinicians overdiagnosed this condition. However, there was a reasonable accuracy for the diagnosis of PSP and FTD. Heterogeneity of the clinical presentation of DLB significantly affected inter-rater agreement and accuracy. The use of multiple diagnostic criteria for cortical and subcortical dementia increases the level of clinical diagnostic accuracy.

Psychosis as a presentation of physical disease in adolescence: a case of Niemann-Pick disease, type C

This study reports the case of a 16-year-old male who presented with a history of prominent psychotic symptoms and paranoid delusions which overshadowed subtle signs and symptoms of cognitive and motor dysfunction. Intensive neurobehavioral and biochemical investigations eventually led to the diagnosis of Niemann-Pick disease, type C (NPC), an autosomal recessively inherited storage disease that is associated with the accumulation of cholesterol in lysosomes and difficulties in the processing of exogenously derived cholesterol. Clues to the presence of a neurological disorder included: a history of insidiously declining academic and athletic performance which antedated the onset of psychosis; abnormalities on mental status examination, including psychomotor slowing, memory difficulties, and impairment of higher attentional functions; physical findings of subtle downgaze impairment, mild symmetrical hyperreflexia, and lower-extremity hypertonia with flexor plantar responses, marked impairment of upper-extremity rapid alternating movements, action tremor, and bilateral posturing with stress gait maneuvers. This case demonstrates the importance of careful and persistent neurodiagnostic evaluation in adolescents with psychotic presentations, particularly when cognitive and motor deterioration is suspected, and even when head CT and MRI scans are judged to be normal.

off absorption, pharmacodynamics, metabolism and excretion of 14C-sumatriptan following intranasal administration to the beagle dog

The pharmacodynamics, pharmacokinetics, metabolism, and excretion of 14C-sumatriptan have been studied in the beagle dog following administration by the intranasal and other routes. The pharmacological response which was monitored, an increase in carotid arterial vascular resistance, correlated with the plasma levels of unchanged sumatriptan following intranasal, intravenous, or intraduodenal administration to the anaesthetised dog. The pharmacokinetics and metabolism of sumatriptan were then confirmed in conscious male and female dogs. Intranasal administration of 14C-sumatriptan resulted in rapid absorption of part of the dose. The overall bioavailability of sumatriptan was 40-50%. Sumatriptan was eliminated from plasma with a half-life of 1.5 or 1.9 h after intravenous or intranasal dosage respectively. Radioactivity was largely excreted in urine (up to 75% of the dose) with small amounts in the bile and faeces after intravenous and intranasal dosing, as sumatriptan and a major metabolite. The results from these studies suggest that intranasal administration provides a viable method for delivering sumatriptan to the systemic circulation.

Low molecular weight GTP-binding proteins are altered in platelet hyperaggregation in IDDM

We examined the hypothesis that hyperaggregating platelets from patients with insulin dependent diabetes mellitus (IDDM) have an alteration in location and function of the guanine nucleotide (GTP)-binding proteins. Platelets from 10 IDDM and 12 age-matched healthy control subjects were collected and washed. Thrombin-induced platelet aggregation (0.025 and 0.05 units for 60 seconds) was increased in IDDM (8.3 +/- 1.8% vs 22.3 +/- 4.4%, P < .05 and 49.9 +/- 7.3% vs 70.9 +/- 7.0%, P < .05). Four small molecular weight GTP-binding proteins were identified by binding of [32P]-GTP on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the cytosol and membranes of these platelets. Each showed specificity for binding [32P]-GTP by competitive inhibition with unlabeled GTP. The total of the 27/28 kDa proteins was decreased in the membrane fraction (414 +/- 30 vs 252 +/- 40 dpm micrograms-1 protein x min, P < .05) and increased in the cytosolic fraction (62 +/- 8 vs 129 +/- 21 dpm unit-1 LDH x min, P < .05) in IDDM. The 21 kDa protein (60.3 +/- 3.5 vs 45.4 +/- 2.9 dpm micrograms-1 protein x min, P < .05) was decreased in platelet membrane in persons with IDDM. In conclusion, increased platelet aggregation in IDDM is accompanied by an altered cellular distribution of a 27/28 kDa GTP-binding protein. These data suggest that the low molecular weight GTP-binding proteins of the 27/28 kDa range may play an important regulatory role in the hyperaggregatory platelets in diabetes.