How can you distinguish symptoms in a stoic patient?

My grandmother is 86-years old. She lives in a skilled nursing facility. Her health history includes very common pain inducing conditions combined, mainly:

trigeminal neuralgia
fibromyalgia
vascular dementia (which has made her a total care patient)
stroke (has resulted in left arm contracture and weakness)
arthritis (especially in the fingers)

After a UTI she was transferred to a nursing facility and placed on hospice.

She did not report trigeminal neuralgia/fibromyalgia-related pain in the months before she stopped communicating, nor did she complain of pain from the other conditions. The only pain she complained of was from a previous fracture in her left shoulder due to a fall. As mentioned before, that entire side has atrophied and weakened after a series of strokes, which have also contributed to her dementia.

She had always been reluctant to disclose pain or discomfort, but in recent weeks she has ceased verbal communication, including any vocalizations (such as groaning) that could indicate discomfort. She displays mostly flat affect, verbally, emotionally and physically, even in situations that used to cause her to express discomfort in some way (such as through a vocalization or grimace). Her lucidity is unclear, but it seems that she drifts in-and-out of alertness and a half-dozing state, but due to her lack of communication, it’s also unclear if this is delirium or disease progression.

Until about 3-4 weeks ago, it was uncommon for her to go multiple days without speaking. But for the last 2 weeks, she has not spoken a word and seems out of it.

Within the last two weeks, she has begun to sleep more throughout the day and wakes intermittently at night despite sleep hygiene practices, daily activities and regular visitation by family, and frequent exposure to sunlight. She spends much of the day sleeping and is nearly impossible to arouse. This pattern was first noticed on 9/28 and she began taking Tylenol the next day. Her current dosage is about 1300 mgs a day.

The only means she communicates any form of pain/discomfort is through furrowing her brow, widening her eyes, slight grimace, closing her eyes (uncommon, but sometimes after being turned/repositioned), and sharp withdrawal of her left foot. Her foot jerks intermittently throughout the day and sometimes wakes her at night. She flinches if touched there. It’s unclear if these responses are due to pain, anxiety/surprise, or due to some other cause. Her left calf is really tight despite stretching.

The hospice and facility doctor don't visit often enough to understand her pain issues. I think it's some kind of neuropathic pain, but I'm not a medical professional. They agreed to put her on Gabapentin, but it's possible that they're doing it just to pacify me considering how often I alert them to her issues.

Based on her previous behavior while being changed, repositioned, and transferred from her Geri chair to bed and vice versa, it’s quite possible that pain proceeds from such activities of daily living. However, due to a lack of visual pain response, it is challenging to tell if she is in discomfort or not. The family has attempted non-pharmacological interventions (warm massage, passive mobility exercises). As the focus is palliative care (reducing the pain/emotional symptoms associated with any health complications, including treating them if need be), the family is seeking further safe solutions for unreported or unnoticed pain responses and depression, as it is unclear if her withdrawal and flat affect/response is due to disease progression or pain/depression.

The family tried Zoloft to stave off depression, but the drug left her sedated. Thus, the family is considering giving her 5 mgs of Lexapro at night to avoid circadian disruptions while addressing any underlying depression/anxiety. When cognizant, she was not one to express sadness. So I’m really not sure if she’s depressed, delirious, or just succumbing to the inevitable progress of vascular dementia.

Unfortunately, the hospice and nursing home haven’t been much help in identifying what (if anything) is abnormal, be it delirium, depression, side effects of Tylenol, post-stroke central neuropathy, etc. I’m working on finding alternative opinions for her care so she can be comfortable.

In the meantime, does anyone have any experience in caring for someone like my grandmother, someone who’s always been really stoic? What have been your experiences in distinguishing between and treating pain (especially nerve pain), depression/anxiety, and delirium?

Thank you so much.