This clinical mind map is almost identical to the clinical mind map on weakness, minus a few diagnoses which cause motor-only weakness, such as ALS and myopathies. This clinical mind map can be used in a similar fashion as the weakness mind map, with some exceptions. Since the patient presentation is a sensory deficit, a clinician must first ask questions to clarify the nature of the deficit. Almost no patient will state the chief complaint as “I have a sensory deficit.” Instead, most patients will use phrases such as “I feel numb,” “I have tingling in such and such area,” “I feel pins and needles in my feet,” or even “I have balance issues.” Almost all of these phrases point out a sensory deficit for which this clinical mind map can be used. A clinician might think that balance problems are not necessarily a sensory deficit, and that is true. Most balance problems are multi-factorial. One of these factors is joint position sense or proprioception, as an appropriate amount of proprioception is required for balance. Since proprioception is one of the components of sensory faculties and is mediated by sensory (dorsal spinal column) pathways, a defect in this sensory pathway can lead to the lack of balance and falls. So, when patients complain about frequent falls or lack of balance, finding out where the primary pathology lies can become a challenge, especially if the problem is multi-factorial. After taking an appropriate history, including the frequency and mechanism of falls, one of the ways for a clinician to determine if the sensory system or dorsal spinal column is involved is to do a physical exam. The chief complaints for the patient presentation of sensory deficit include 1) numbness, 2) tingling, and 3) balance or falls related to balance, which is related to dorsal spinal column. After a clinician has clarified the exact nature and type of the deficit, probable diagnoses must be considered, and it is usually easy to narrow the list of differentials early in the process because most patients will include information about the extent and location of sensory deficit when describing their chief complaint. Urgent and emergent situations can be addressed by reviewing vitals and appearance and asking about the duration or acuteness of symptoms and any toxic exposure. Life-threatening diagnoses corresponding to urgent/emergent situations are GBS, Spinal Cord Lesions, and CVA, including intracranial infarction and hemorrhage. The process of weighing can be performed by asking diagnoses specific or focused follow up questions. The main high yield questions are the location, duration, and pattern (fluctuating or not). Finally, anchor bias must be removed by asking additional questions. A physical exam and pertinent diagnostic tests help arrive at the final diagnosis.
A helpful mnemonic to remember differential diagnoses on this mind map is to think 3/3/1 meaning 3 conditions related to central nervous system, 3 to peripheral nerves and 1 other.