Occipital Neuralgia: This condition involves irritation or inflammation of the occipital nerves, which can cause numbness, tingling, and sometimes pain in the back of the head. The absence of head pain in this case does not rule out this diagnosis, as some patients may experience numbness or tingling without significant pain.

Migraine: Although the patient does not report head pain, some migraines can present with neurological symptoms like numbness and tingling without headache, known as "acephalgic migraine" or "migraine aura without headache."
Trigeminal Neuralgia: While this condition typically affects the face, it can sometimes cause symptoms in the back of the head, especially if the occipital nerves are involved. However, it usually presents with intense pain.
Multiple Sclerosis (MS): MS can cause a wide range of neurological symptoms, including numbness and tingling. The symptoms can be localized to one area, such as the back of the head, and may not necessarily be accompanied by pain.

Stroke or Transient Ischemic Attack (TIA): Although less likely given the localized nature of the symptoms and the absence of other neurological deficits, stroke or TIA must be considered, especially if the numbness and tingling are new, sudden, and transient.
Brain Tumor: A tumor in the brain could potentially cause localized numbness and tingling, depending on its location. This would be a concern if the symptoms are progressive or if there are other signs of increased intracranial pressure.
Infections (e.g., Meningitis, Encephalitis): Infections of the brain or meninges can cause a variety of neurological symptoms, including numbness and tingling, although these conditions are typically accompanied by fever, headache, and other systemic signs.

Neurosyphilis: A late manifestation of syphilis infection, neurosyphilis can cause a wide range of neurological symptoms, including numbness and tingling, although this would be an uncommon presentation.
Sjögren's Syndrome: This autoimmune disorder can cause neurological symptoms, including numbness and tingling, due to inflammation of the nerves, but it is less common and usually associated with other systemic symptoms like dry eyes and mouth.
Vitamin Deficiencies (e.g., Vitamin B12 Deficiency): Deficiencies in certain vitamins, particularly B12, can cause neurological symptoms, including numbness and tingling, but these would typically be more widespread and accompanied by other signs of deficiency.