Introduction: A retrospective case series of acute intermittent porphyria (AIP) presenting with acute quadriparesis is described with a focus on patterns of neuropathy and nerve conduction study findings.Methods: Six patients with acute polyneuropathy were diagnosed with AIP on the basis of characteristic clinical findings, urine porphobilinogen levels, and pathogenic variants in the hydroxymethylbilane synthase gene. Vital function impairment, neuropathic patterns, serial changes in nerve conduction studies (NCS), and laboratory findings are reviewed.Results: A total of six patients with acute porphyric neuropathy were included. Patterns of weakness varied between upper and lower extremities. Three patients exhibited allodynia with preservation of large fiber sensory modalities in the acute polyneuropathy phase. Initial NCS revealed motor axonal polyneuropathy in four patients with sparing of motor conduction velocities and latencies. Relative sparing of tibial compound muscle action potential amplitudes is seen in two patients. Serial NCS revealed interval reduction of compound muscle action potential amplitudes in the upper extremity only in one patient and selective reduction of sensory nerve action potential amplitudes of the lower extremity in another patient. There were substantial delays in diagnoses, with all but one patient misdiagnosed as GBS. All but two patients required ambulation aids at last follow‐up assessment.Conclusion: The findings in this series show variability in neuropathic patterns and NCS changes over time in AIP presenting with acute polyneuropathy. Small fiber neuropathy and allodynia with sparing of large fiber sensory modalities may serve as a diagnostic clue guiding early recognition of AIP in patients presenting with acute polyneuropathy.

The prevalence of dementia and mild cognitive disorder has markedly risen in recent years. Alzheimer's disease (AD) stands out as the most common form of neurodegenerative dementia among the elderly, featuring progressive memory loss and cognitive decline. Although the exact biological causes of AD are complex and multifactorial, genetics is considered a prominent contributor. To date, around 80 genetic loci have been identified, primarily in European ancestry groups, though a considerable portion of AD’s genetic architecture remains elusive. Recognizing the impending rise in AD cases, both governmental and private sectors in Saudi Arabia are making efforts to enhance formal care and services for older adults. While few studies have investigated AD-susceptible genes within the Saudi population, further attention is needed to explore the genetic background and identify molecular biomarkers associated with AD. This review provides an overview of the current understanding of AD and recent genetic research in Saudi Arabia.

Background: Approximately half of patients with diabetes mellitus (DM) develop diabetic distal symmetric sensorimotor polyneuropathy (DM-DSPN), yet no reliable biomarkers for its early detection exist. This study assesses cystatin C (CysC), a naturally occurring protein, in diabetic persons with and without large-fiber DM-DSPN. Methods: This study involved persons with diabetes (HbA1c > 6.5%) visiting specialized diabetic clinics at King Saud University Medical City (KSUMC) in Riyadh, Saudi Arabia. Clinical features, laboratory data, nerve conduction findings, and serum CysC levels were assessed. DM-DSPN was diagnosed if signs of large nerve fiber impairment were present in the lower extremity in a symmetric and length-dependent pattern. Participants were designated as diabetic with or without large-fiber DSPN (+DM/+DSPN and +DM/−DSPN, respectively) based on validated composite scores of nerve conduction attributes. Results: A total of 52 persons with diabetes were included for analysis (24 with +DM/+DSPN and 28 with +DM/−DSPN). One participant had type 1 DM; all remaining participants had type 2 DM. In multivariate regression, serum CysC ≥ 0.88 mg/L was significantly associated with DM-DSPN. Serum CysC was significantly associated with peroneal and ulnar compound muscle action potential amplitudes (p-value = 0.003 and p-value = 0.03, respectively) and peroneal and tibial motor nerve conduction velocities (p-value = 0.009 and p-value = 0.0003, respectively). Conclusions: Serum CysC levels > 0.9 mg/L are associated with DM-DSPN (86% sensitivity and 81% specificity), independently of HbA1c or GFR. Serum CysC is also associated with peroneal and ulnar compound muscle action potential amplitudes and peroneal and tibial motor nerve conduction velocities. Larger studies are needed to determine the role of CysC as a potential biomarker of DM-DSPN.