Challenging cognitive cases among physician populations: case vignettes and recommendations.

BACKGROUND: Physicians are not immune to cognitive impairment. Because of the risks created by practising doctors with these issues, some have suggested developing objective, population-specific measures of evaluation and screening guidelines to assess dysfunction. However, there is very little published information from which to construct such resources. AIMS: To highlight the presentation characteristics and provide evaluation recommendations specific to the needs of physicians with actual or presumed cognitive impairment. METHODS: A retrospective database and chart review of cognitively impaired doctors who presented to a physician health programme (PHP). Complex cases were highlighted using simple descriptives and clinical vignettes. RESULTS: A total of 124 cases were included. Clients presented with a variety of issues other than cognitive concerns. We identified four principal domains of impairment: (i) diseases of (or in) the brain (48%); (ii) mood/ anxiety disorders or treatment side effects (28%); (iii) substance use (9%) and (iv) traumatic brain injury (7%). Age was not a good predictor of impairment and brief screening using the Montreal Cognitive Assessment demonstrated a ceiling effect with this cohort. Although many clients underwent some type of professional or personal transition, impairment did not necessarily indicate worse functioning after care. CONCLUSIONS: Physician cognitive evaluations should consider a variety of secondary sources of information, particularly vocational performance reports. It may take time before cognitive impairment can be diagnosed or ruled-out in this population. Prior assumptions, especially for non-cognitive referrals, can lead to inaccurate diagnosis and referrals. PHPs must manage cognitive cases carefully, not only in their clinical complexity but also in their psychosocial aspects.

Inhibitory effect of increased photoperiod on wool follicle growth.

The relationships between circulating prolactin (PRL), wool follicle growth and daylength were investigated in 24 New Zealand Wiltshire ewes housed indoors from September 1989 to May 1991. Twelve control (C) ewes were maintained under natural photoperiod. Two other groups were held in short days (SD; 8 h light: 16 h darkness) commencing from the winter solstice (22 June 1990) for either three (group SD3, n = 7) or six (group SD6, n = 5) months before reversion to natural daylength. Skin was sampled at one- to four-week intervals for histological determination of percentages of growing primary and secondary follicles. Hourly blood samples over 24 h were collected via jugular cannulae from C sheep in March and July and then monthly from all animals until December 1990 for estimation of mean monthly PRL concentrations for each treatment group. Between autumn (March 1990) and winter (July) primary follicle activity (PFA) and secondary follicle activity (SFA) declined in C ewes (PFA: 97 to 43%, SFA: 100 to 57%). Follicle regrowth during July and August in eight C ewes preceded the initial rise in plasma PRL from the winter minimum (1.6 ng/ml). Across the three groups, four instances of decreased follicle activity were observed, closely following or concurrent with increases in plasma PRL concentrations. The resumption of spring growth in four C sheep was temporarily checked by falls in follicle activities during September and October as PRL concentrations began to increase (3.4 to 8.9 ng/ml). Follicle activity also declined in November and December in eight C sheep, coincident with the rapid rise in PRL to a seasonal maximum in late November (165.4 ng/ml). The increase in SD3 follicle activity over spring was not delayed by short days but during October, after release from treatment, PRL concentrations rose (1.8 to 12.0 ng/ml) and follicle activity declined (PFA: 65 to 38%, SFA: 68 to 43%). In SD6 ewes, PRL concentrations were suppressed (2.1 ng/ml) and relatively constant levels of follicle activity (PFA: 73%, SFA: 95%) were maintained throughout short-day treatment. Release of SD6 ewes into summer photoperiod in January 1991 temporarily interrupted follicle growth (PFA: 68 to 17%, SFA: 96 to 19%) and caused out-of-season shedding in March and April. Contemporary C follicle activities were high (PFA: 95%, SFA: 98%). These data suggest that natural and experimental increases in daylength have a short-term inhibitory effect on growing wool follicles which could be mediated through rising concentrations of plasma prolactin.

The microanatomy, cell replication, and keratin gene expression of hair follicles during a photoperiod-induced growth cycle in sheep.

Exposure of New Zealand Wiltshire sheep to long days, following 24 weeks of short days, caused a synchronised out-of-season wool follicle growth cycle. Skin biopsies were collected at intervals between 3 and 30 days and follicles were examined by light microscopy in both transverse and longitudinal section to describe the regressive (catagen), resting (telogen) and regenerative (proanagen) stages of the induced growth cycle. Follicles were generally in the growing phase (anagen) during short day treatment but by day 20 after exposure to long day photoperiod. 16% of follicles were in late catagen. By day 52, all follicles were in various stages of catagen, telogen and proanagen. The progression through the cycle occurred more slowly, but was morphologically similar to follicle growth cycles reported in rodents and goats, induced by plucking or melatonin, respectively. Follicles in early catagen were rarely observed, possibly reflecting the brevity of this phase of the cycle. Late catagen follicles were distinguished by the presence of a brush end and an inner root sheath, the latter disappearing as follicles entered telogen. Immunocytochemistry of proliferating cell nuclear antigen provided evidence that mitotic activity in the follicle bulb ceased completely during the brief telogen phase. The simultaneous absence of type I intermediate filament keratin mRNA indicated that keratinocyte differentiation had also been interrupted. Cell proliferation was re-established in early proanagen prior to observable changes in the follicle microanatomy. The relatively synchronised follicle growth cycle induced by photoperiod manipulation represents a potentially useful model for the study of changes in follicle ultrastructure and the endocrine and biochemical regulation of seasonal hair growth patterns.

Fiber growth initiation in hair follicles of goats treated with melatonin.

The sequence of structural changes in goat hair follicles was investigated using melatonin implants to advance and synchronize spring hair growth. Ten pasture fed cashmere wethers each received a controlled release formulation of 70 mg of melatonin on September 1 1989, and showed plasma melatonin elevated above physiological levels over 14 days post-treatment (914 +/- 154 pg/ml [mean +/- SEM] on day 14). In ten untreated animals, daytime plasma melatonin was 19.9 +/- 4.7 pg/ml. Histological examination of skin biopsies taken over the 14 days from the start of the experiment showed that primary hair follicles of goats with manipulated hormone levels had initiated fiber growth (entered proanagen), whereas primary follicles of untreated goats largely remained in the quiescent phase (telogen). A standardized terminology was used to describe the sequence of events during induced proanagen. Structural reorganization of follicles began in treated animals between days 6 and 12 post-treatment, and emergent fibers grew by day 24. Advancement of spring fiber growth was associated with a suppression of the normal rise in plasma prolactin concentration. Prolactin levels in untreated goats increased from 7.4 +/- 1.8 ng/ml on day 1 to 12.8 +/- 1.6 ng/ml on day 14, but declined in treated goats from 6.3 +/- 2.3 ng/ml to 2.2 +/- 0.8 ng/ml over the same period.