Primitive reflexes in healthy, adult volunteers and neurological patients: methodological issues

The grasp reflex in patients with idiopathic normal pressure hydrocephalus

OBJECTIVE

To investigate the prevalence and intensity of grasp reflexes and to examine changes in these reflexes after shunt surgery in patients with idiopathic normal pressure hydrocephalus (iNPH).

METHODS

We enrolled 147 patients with probable iNPH. A standard procedure was used to determine the presence of grasp reflexes, and the intensity of these reflexes was assessed using a four-category classification. Clinical rating scales and their correlation with grasp reflexes were also evaluated. Grasp reflexes were reassessed in 72 patients 1 year after surgery.

RESULTS

We found that approximately 50.3% of patients with iNPH exhibited a positive grasp reflex. Among these patients, 69% exhibited bilateral positivity, while the remaining patients showed unilateral positivity. Furthermore, the intensity of the grasp reflex was significantly correlated with the severity of gait and with cognitive, urinary, motor, and behavioural symptoms. Surgical interventions led to a reduction (41.7%) or maintenance (30.6%) of the reflex intensity in 72.3% of iNPH patients. The changes in reflex intensity showed significant positive correlations with changes in the number of steps of the Timed Up and Go test and Trail Making Test-A scores but not with changes in total scores on the iNPH Grading Scale.

CONCLUSION

This retrospective study identified grasp reflexes as a highly prevalent phenomenon in patients with iNPH. These reflexes can assist in evaluating the severity of various symptoms, including cognitive, gait, urinary, motor and emotional symptoms.

Primitive reflexes and dementia in older adults: a meta-analysis of observational and cohort studies

Primitive reflexes (PRs) are clinical signs that indicate diffuse cerebral dysfunction and frontal lesions. We aimed to present a comprehensive analysis of the prevalence and risk of PRs in patients with dementia. English-language articles published from January 1990 to April 2021 were searched in PubMed, ScienceDirect, Cochrane, and Web of Science with keywords. The titles and abstracts of the identified articles were screened to identify potentially relevant papers. Odds ratios and risk ratios were extracted with 95% confidence intervals and combined using the random-effects model after logarithmic transformation. The prevalence in dementia patients was also combined using the random-effects model. This meta-analysis involved 29 studies. The snout reflex (48% of cases) was the most prevalent. It was found that the risk of PRs in individuals with dementia was significantly elevated, ranging from 13.94 to 16.38 times higher than in healthy controls. The grasp reflex exhibited the highest risk for dementia. This meta-analysis showed that the prevalence and the risk of PRs is high in older patients with dementia. Therefore, PRs, especially the grasp reflex, should be carefully assessed as a part of routine physical examination in the diagnostic process for dementia.

Inter-rater reliability of primitive signs in dementia

OBJECTIVES

The aim of the present study is to explore inter-rater reliability of primitive signs in a group of patients assessed for dementia.

PATIENTS AND METHODS

97 patients admitted to our University Hospital for cognitive impairment were enrolled in the study. The mean age was 73.04 ± 8.68 (53 females and 44 males). All patients were examined by two cognitive neurologists in a blind fashion. The grasp reflex, the snout reflex, the glabella tap reflex and the palmomental reflex were elicited according to the current literature. Moreover, we add a stretch reflexes (the masseter reflex) to our battery.

RESULTS

The most frequent primitive reflex was the palmomental reflex followed by the glabella tap, snout, and grasp. The inter-rater reliability was measured for each primitive reflex: grasp reflex (0.884) have a strong correspondence; the glabella tap (0.556), the palmomental (0.516) and the snout reflex (0.445) have otherwise a weak correspondence. The masseter reflex reaches a moderate agreement (0.662). All the measurements reached statistical significance (p < 0.005).

CONCLUSION

The results of the study show weak to substantial agreement for primitive signs and the masseter reflex as expressed by the low-to-high kappa values.

Neurological soft signs and cognitive performance in early childhood

Neurological soft signs (NSSs), minor neurological abnormalities, have been implicated as risk factors for poor cognitive performance in small-scale studies. Here we investigate the associations between NSSs and multiple domains of cognitive performance in a large, population-based cohort and evaluate sex differences in these associations. We analyzed data from 35,710 seven-year-old children in the Collaborative Perinatal Project to study the association between the number of NSSs and cognitive test scores using multiple linear regression models adjusting for risk factors for brain injury and aberrant neurodevelopment. NSSs were associated with lower scores on all domains of cognitive performance. Each additional soft sign was associated with lower full-scale IQ (b = -4.83, 95% CI [-5.06, -4.60]), performance IQ (b = -4.28, 95% CI [-4.54, -4.02]), and verbal IQ scores (b = -4.53, 95% CI [-4.76, -4.30]), as well as arithmetic (b = -4.06, 95% CI [-4.26, -3.85]), spelling (b = -3.53, 95% CI [-3.75, -3.30]), and reading (b = -4.00, 95% CI [-4.26, -3.75]) scores on the Wide Range Achievement Test (WRAT). Only one sex difference was observed: The association between NSS and the WRAT spelling test was somewhat stronger in girls (b = -4.01, 95% CI [-4.26, -3.36]) than in boys (b = -3.53, 95% CI [-3.75, -3.30]). There is an association between NSSs and poor cognitive performance that is not attributable to established risk factors for brain injury and aberrant neurodevelopment. Further research is needed to investigate the mechanisms underlying this association and to determine if interventions targeting NSS in children might have beneficial effects on neurocognitive development. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

[Cortical Release Signs in Patients with Schizophrenia, Depressive Disorders, and Bipolar Affective Disorder]

BACKGROUND AND OBJECTIVES

Determining the presence of cortical release signs associated with white matter damage, is a clinically easy method to perform. The objective of this study is to determine the presence of cortical release signs in patients with mental illnesses and cerebrovascular disease, as well as its clinical usefulness, given that it indicates cortical damage.

MATERIAL AND METHODS

A review was made of cortical release signs in patients hospitalized in clinical psychiatry and general hospitals with bipolar affective disorder (40), depression (37), schizophrenia (33), cardiovascular disease (33) and dementia (37).

RESULTS

The signs of cortical release do not have the same importance as cortical damage. For example, the glabellar reflex was found in all the groups, that of paratonia, particularly in the group with schizophrenia, and others signs in the group of patients with dementia.

CONCLUSIONS

It is suggested that these signs imply subcortical white matter damage. The appearance of these signs shows the need for a follow up of patients diagnosed with bipolar affective disorder, depression and schizophrenia.

An Update on the Italian Twin Register: Advances in Cohort Recruitment, Project Building and Network Development

The Italian Twin Register has been in place for more than 10 years. Since its establishment, it has been focusing, on the one hand, on a continuous update of the existing information, and on the other hand, on new phenotypes and sample collection. Demographic data on about 140,000 twins have been updated using the municipality registries. The Italian Twin Register has been carrying out several new studies during the last few years. A birth cohort of twins, Multiple Births Cohort Study, has been started and the enrolment is ongoing. For this cohort, data on pregnancy and birth are collected, and periodical follow-ups are made. DNA is being collected for the twins and their parents. In the area of behavioral genetics, most efforts have been directed to psychological well being assessed with self-reported tools. Research on age-related traits continues with studies on arteriosclerosis development, early biomarkers in mild cognitive impairment, and the relation between lifestyle habits and mutagen sensitivity. The Italian Twin Register biobanking has grown in its size and in its know-how in terms of both technical issues and ethical procedures implementation. Furthermore, attitudes toward biobank-based research, together with willingness and motivation for donation, are being investigated. A valuable key resource for the Italian Twin Register is the possibility of linking twin data with disease registries. This approach has been yielding several important results, such as the recent study on the heritability of type 1 diabetes.

The grasp reflex: a symptom in need of treatment

The grasp reflex is one of the primitive reflexes frequently observed in neurodegenerative diseases. However, quality of life and treatment of the grasp reflex are neglected in the literature. Following two brief case vignettes of patients seen recently who experienced disability from a grasp reflex, we briefly review its phenomenology, anatomy-physiology and epidemiology in neurodegenerative movement disorders, and assess the limited current literature regarding the quality of life and treatment.

Prevalence of primitive reflexes and the relationship with cognitive change in healthy adults

OBJECTIVES

Primitive reflexes (PR) generally disappear early in life but may reappear later, in which case they are often associated with chronic neurological conditions, such as dementia or Parkinson's disease. Studies have shown that the presence of PRs may be indicative of both the severity and rate of progression of these diseases and may be the result of disinhibition of cortical networks. The association between PRs and cognitive function in usual ageing is unclear. We investigated whether the occurrence, amplitude, and persistence of four nociceptive (glabbelar tap, palmomental, pollicomental, and snout reflexes), three prehensile reflexes (suck, palmar grasp, and rooting), and two other reflexes (mouth open finger-spread and nuchocephalic reflexes) were related to performance in specific cognitive domains in normal ageing individuals.

METHODS

Four-hundred and seventy normal aging participants (25-82 years) in the Maastricht Aging Study (MAAS), were included in the study. They were neurologically and cognitively screened at baseline and were retested after 3 (only individuals aged 50 years and older at baseline) and 6 years.

RESULTS

The prevalence of most PRs increased with age: 47% of men aged 25-45 years had at least one PR, compared with 73% of men aged 65-85 year (p = 0.002). In women these percentages were 51 and 75, respectively (p=0.008). The prevalence, amplitude, and persistence of PRs were unrelated to cognition at baseline or at the 3- or 6-year follow-up.

CONCLUSIONS

The prevalence of particularly nociceptive reflexes rises substantially with increasing age in normal individuals. However, the presence of PRs cannot be considered to be a marker of cognitive decline in normal aging individuals.

Primitive reflexes and cognitive function

BACKGROUND: Data on the prevalence of primitive reflexes (PR) in adulthood, their pathological significance and relationship to age and cognition are controversial. OBJECTIVE: To study the relationship between PR and cognition in 30 patients with probable Alzheimer's disease (AD) and 154 control subjects. METHOD: Diagnosis of probable AD was based on DSM-IV, NINCDS-ADRDA, and CAMDEX criteria. Primitive reflexes were quantified from zero (absent) to 1 (mild) or 2 (markedly present). The Cognitive Abilities Screening Instrument - Short Form (CASI-S) was used to evaluate registration, temporal orientation, verbal fluency and recall. A drawing test was added. RESULTS: Most frequent PR among demented and controls were suck (77% and 62%, respectively) and snout (60% and 27%), followed by glabellar (30% and 19%), paratonia (37% and 5%), and palmomental (23% and 5%). None of controls had more than three PR. Frequency of PR tended to increase with age and cognitive deterioration. Grasp and Babinski responses were found only in dementia patients. Primitive reflexes were not correlated with each other, except snout with suck, and snout with glabellar reflex. CONCLUSION: The finding of grasp and Babinski sign, or the presence of more than three primitive signs, particularly the combination of paratonia, snout, suck, and palmomental reflexes strongly suggests brain dysfunction, especially when these signs are marked and accompanied by deficits in orientation, recall, verbal fluency, and constructional praxis.

Cortical release signs in psychiatry

OBJECTIVE

To review the role of cortical release signs (CRS) in neuropsychiatry.

METHOD

A thorough literature review was conducted using Medline and Psychlit databases, and other relevant references available to the authors.

RESULTS

A number of neurological abnormalities are reported at elevated rates in neuropsychiatric conditions. CRS are a group of primitive reflexes that are present in the neonate but become inhibited as the infant central nervous system (CNS) develops, only to later re-emerge in the context of CNS disease. The clinical elicitation and interpretation of each CRS is described with reference to its neurobiology. The prevalence of CRS in schizophrenia, affective disorder, obsessive-compulsive disorder, Alzheimer's disease, vascular dementia, frontotemporal dementia and other neuropsychiatric illness allows for their use in the clinical management of these patients, including diagnostic assessment, treatment monitoring and prognosis.

CONCLUSIONS

A number of issues complicate their interpretation in neuropsychiatric illness, including the apparent high base rate of some CRS in non-clinical populations, their increasing prevalence with age, lack of specificity and uncertainty over what constitutes an 'abnormal' response. In some circumstances, CRS may assist in diagnostic differentiation and illness staging.

Elbow flexion response as another primitive reflex

In daily clinical practice we noticed that patients with intellectual impairment spontaneously flex the elbow within a few seconds of the forearm being manipulated during routine examination of spasticity of the muscles in the upper extremities. We termed this phenomenon elbow flexion response (EFR), and prospectively studied it in 229 patients who underwent in-hospital rehabilitation following brain damage. Evaluation of each patient included EFR, patient profile, ability to communicate, scores on three parameters from various intelligence tests, scores on seven parameters testing primitive reflexes, and scores on three parameters describing personality. We investigated for relationships among these parameters. Consequently, although EFR rarely have a statistical association with the varied profiles of patients, patients with bilateral lesion or bilateral paresis demonstrated significantly more marked EFR than those with unilateral lesion or unilateral paresis. Patients with involvement of the frontal lobe showed significantly more marked EFR than those without damage in this area. Elbow flexion responses occurred significantly more frequently in relation with lower scores on intelligence and occurred with significantly higher frequency in conjunction with the more marked appearance of conventional primitive reflexes. Therefore, we conclude that EFR have a strong association with intelligence and with the existence of frontal lobe lesion, and their mode of clinical presentation parallels that of primitive reflexes particularly that of the grasp reflex. We propose that EFR could be referred as a variation of the grasp reflex occurring in the more proximal or axial part of the body.

Inter-rater reliability of the neurological examination in schizophrenia

Neurological Examination Abnormalities (NEA) are prevalent in schizophrenia, but the significance of this is obscured by methodological problems. The Neurological Evaluation Scale (NES), the most widely used structured neurological examination in schizophrenia research, has had limited study of its inter-rater reliability (IRR). An augmented version of the NES was jointly administered (one examiner-rater and one observer-rater) by three pairs of psychiatrists to two populations of patients with idiopathic psychotic disorders. In addition to the ordinal and categorical data yielded by the original NES, continuous data were recorded in one of the series. Reliability analyses of our populations and a previously published study, reveal consistently adequate IRR in 12 of the 26 items assessed, and inconsistently adequate IRR in an additional 11. Consistent with studies using other NEA schedules, IRR was unacceptably low for some items that rely on subjective severity ratings. Certain rare abnormalities, which posed difficulties for the estimation of IRR, are probably not generally useful in the study of schizophrenia. Reliability estimates of continuous, ordinal and dichotomous data were comparable in most cases. We recommend that certain items from the NES be deleted, and that other studies of NEA in psychiatry follow similar procedures before undertaking further analyses.

Agreement between the neonatal neurological examination and a standardized assessment of neurobehavioural performance in a group of high-risk newborns

The degree of agreement between the neonatal neurological examination and a standardized neurobehavioural assessment was investigated in a group of 32 newborns with congenital heart defects. A paediatric neurologist performed a neurological examination, and an occupational therapist administered the Einstein Neonatal Neurobehavioural Assessment Scale on all subjects. Both examiners independently evaluated each subject, and were blinded to the diagnosis, to perinatal status and to each other's clinical findings. Statistical analysis demonstrated a significant association between the overall impression between both examiners (p < .0001), with a crude agreement of 96.9%. Sixteen neonates were determined to be normal and 15 abnormal by both examiners, with disagreement in only one subject. Although two distinct approaches were employed in the neurological assessment of high-risk newborns, both assessments evaluate the maturity and integrity of the immature central nervous system. The results demonstrate a strong agreement between these two approaches, suggesting that the neonatal neurological examination is consistent and valid.

Neurological findings in the normal elderly: prevalence and relationships with memory performance

Data on the presence of neurological signs in the normal elderly are scanty, and data on their possible relationships to memory performances are not available. Three-hundred and ninety-six subjects born in 1925 and living in Pavia, who were recruited for a larger study on memory impairment in the elderly, underwent a standardized neurological examination (SNE) consisting of 22 items, an anamnestic interview and a memory test battery. A high number of signs was found, particularly for regressive reflexes (snout in 50% of cases). There was a tendency for several alterations to be found in the same subject. Accordingly, four clusters of signs were identified. Diabetes mellitus, hypertension, heart disease or past head trauma were not consistently associated with SNE scores. While memory impairment was also not consistently associated with SNE scores, there was a higher tendency for memory-impaired subjects to show at least one abnormal SNE score.

Primitive reflexes in Alzheimer's disease and vascular dementia

Data on the prevalence and clinical value of primitive reflexes (PRs) in dementia are controversial, mainly due to a lack of standardization of the methods by which these signs are elicited and scored. A standardized protocol was used to investigate eight PRs in 20 patients with Alzheimer's disease (AD), 20 patients with vascular dementia (VD), and 20 control subjects for each group. Both patient groups showed considerably more PRs than the control groups. The prevalence of PRs was related to the severity of dementia. No single reflex or combination of PR pathognomonic for dementia could be distinguished. The PR profile of AD and VD patients were similar.